cpython_chunk_13.py

# Auto-generated from cpython_chunk_13.txt

TEXT_DATA = r"""
.. bpo: 36052
.. date: 2019-02-20-17-57-31
.. nonce: l8lJSi
.. release date: 2019-02-25
.. section: Core and Builtins
Raise a :exc:`SyntaxError` when assigning a value to ``__debug__`` with the
Assignment Operator. Contributed by Stéphane Wirtel and Pablo Galindo.
..
.. bpo: 36012
.. date: 2019-02-19-10-47-51
.. nonce: xq7C9E
.. section: Core and Builtins
Doubled the speed of class variable writes.  When a non-dunder attribute was
updated, there was an unnecessary call to update slots.
..
.. bpo: 35942
.. date: 2019-02-18-09-30-55
.. nonce: oLhL2v
.. section: Core and Builtins
The error message emitted when returning invalid types from ``__fspath__``
in interfaces that allow passing :class:`~os.PathLike` objects has been
improved and now it does explain the origin of the error.
..
.. bpo: 36016
.. date: 2019-02-17-20-23-54
.. nonce: 5Hns-f
.. section: Core and Builtins
``gc.get_objects`` can now receive an optional parameter indicating a
generation to get objects from. Patch by Pablo Galindo.
..
.. bpo: 1054041
.. date: 2019-02-16-00-42-32
.. nonce: BL-WLd
.. section: Core and Builtins
When the main interpreter exits due to an uncaught KeyboardInterrupt, the
process now exits in the appropriate manner for its parent process to detect
that a SIGINT or ^C terminated the process.  This allows shells and batch
scripts to understand that the user has asked them to stop.
..
.. bpo: 35992
.. date: 2019-02-14-12-01-44
.. nonce: nG9e2L
.. section: Core and Builtins
Fix ``__class_getitem__()`` not being called on a class with a custom
non-subscriptable metaclass.
..
.. bpo: 35993
.. date: 2019-02-14-09-17-54
.. nonce: Bvm3fP
.. section: Core and Builtins
Fix a crash on fork when using subinterpreters. Contributed by Stéphane
Wirtel
..
.. bpo: 35991
.. date: 2019-02-14-00-00-30
.. nonce: xlbfSk
.. section: Core and Builtins
Fix a potential double free in Modules/_randommodule.c.
..
.. bpo: 35961
.. date: 2019-02-12-20-16-34
.. nonce: 7f7Sne
.. section: Core and Builtins
Fix a crash in slice_richcompare(): use strong references rather than stolen
references for the two temporary internal tuples.
..
.. bpo: 35911
.. date: 2019-02-06-17-50-59
.. nonce: oiWE8
.. section: Core and Builtins
Enable the creation of cell objects by adding a ``cell.__new__`` method, and
expose the type ``cell`` in ``Lib/types.py`` under the name CellType. Patch
by Pierre Glaser.
..
.. bpo: 12822
.. date: 2019-02-05-12-48-23
.. nonce: 0x2NDx
.. section: Core and Builtins
Use monotonic clock for ``pthread_cond_timedwait`` when
``pthread_condattr_setclock`` and ``CLOCK_MONOTONIC`` are available.
..
.. bpo: 15248
.. date: 2019-02-04-21-10-17
.. nonce: 2sXSZZ
.. section: Core and Builtins
The compiler emits now syntax warnings in the case when a comma is likely
missed before tuple or list.
..
.. bpo: 35886
.. date: 2019-02-01-18-12-14
.. nonce: 0Z-C0V
.. section: Core and Builtins
The implementation of PyInterpreterState has been moved into the internal
header files (guarded by Py_BUILD_CORE).
..
.. bpo: 31506
.. date: 2019-01-22-02-06-39
.. nonce: eJ5FpV
.. section: Core and Builtins
Clarify the errors reported when ``object.__new__`` and ``object.__init__``
receive more than one argument. Contributed by Sanyam Khurana.
..
.. bpo: 35724
.. date: 2019-01-11-14-46-08
.. nonce: Wv79MG
.. section: Core and Builtins
Signal-handling is now guaranteed to happen relative to the main
interpreter.
..
.. bpo: 33608
.. date: 2018-09-15-12-13-46
.. nonce: avmvVP
.. section: Core and Builtins
We added a new internal _Py_AddPendingCall() that operates relative to the
provided interpreter.  This allows us to use the existing implementation to
ask another interpreter to do work that cannot be done in the current
interpreter, like decref an object the other interpreter owns.  The existing
Py_AddPendingCall() only operates relative to the main interpreter.
..
.. bpo: 33989
.. date: 2018-08-08-20-52-55
.. nonce: TkLBui
.. section: Core and Builtins
Fix a possible crash in :meth:`list.sort` when sorting objects with
``ob_type->tp_richcompare == NULL``.  Patch by Zackery Spytz.
..
.. bpo: 35512
.. date: 2019-02-24-00-04-10
.. nonce: eWDjCJ
.. section: Library
:func:`unittest.mock.patch.dict` used as a decorator with string target
resolves the target during function call instead of during decorator
construction. Patch by Karthikeyan Singaravelan.
..
.. bpo: 36018
.. date: 2019-02-21-15-47-00
.. nonce: qt7QUe
.. section: Library
Add statistics.NormalDist, a tool for creating and manipulating normal
distributions of random variable.  Features a composite class that treats
the mean and standard deviation of measurement data as single entity.
..
.. bpo: 35904
.. date: 2019-02-16-00-55-52
.. nonce: V88MCD
.. section: Library
Added statistics.fmean() as a faster, floating-point variant of the existing
mean() function.
..
.. bpo: 35918
.. date: 2019-02-11-16-23-10
.. nonce: oGDlpT
.. section: Library
Removed broken ``has_key`` method from
multiprocessing.managers.SyncManager.dict. Contributed by Rémi Lapeyre.
..
.. bpo: 18283
.. date: 2019-02-11-09-24-08
.. nonce: BT3Jhc
.. section: Library
Add support for bytes to :func:`shutil.which`.
..
.. bpo: 35960
.. date: 2019-02-10-20-57-12
.. nonce: bh-6Ja
.. section: Library
Fix :func:`dataclasses.field` throwing away empty mapping objects passed as
metadata.
..
.. bpo: 35500
.. date: 2019-02-10-00-00-13
.. nonce: 1HOMmo
.. section: Library
Write expected and actual call parameters on separate lines in
:meth:`unittest.mock.Mock.assert_called_with` assertion errors.  Contributed
by Susan Su.
..
.. bpo: 35931
.. date: 2019-02-07-16-22-50
.. nonce: _63i7B
.. section: Library
The :mod:`pdb` ``debug`` command now gracefully handles syntax errors.
..
.. bpo: 24209
.. date: 2019-02-06-01-40-55
.. nonce: awtwPD
.. section: Library
In http.server script, rely on getaddrinfo to bind to preferred address
based on the bind parameter. Now default bind or binding to a name may bind
to IPv6 or dual-stack, depending on the environment.
..
.. bpo: 35321
.. date: 2019-02-02-01-53-36
.. nonce: 1Y4DU4
.. section: Library
Set ``__spec__.origin`` of  ``_frozen_importlib`` to frozen so that it
matches the behavior of ``_frozen_importlib_external``.  Patch by Nina
Zakharenko.
..
.. bpo: 35378
.. date: 2019-01-21-02-15-20
.. nonce: 4oF03i
.. section: Library
Fix a reference issue inside :class:`multiprocessing.Pool` that caused the
pool to remain alive if it was deleted without being closed or terminated
explicitly. A new strong reference is added to the pool iterators to link
the lifetime of the pool to the lifetime of its iterators so the pool does
not get destroyed if a pool iterator is still alive.
..
.. bpo: 34294
.. date: 2019-01-14-11-53-10
.. nonce: 3JFdg2
.. section: Library
re module, fix wrong capturing groups in rare cases. :func:`re.search`,
:func:`re.findall`, :func:`re.sub` and other functions that scan through
string looking for a match, should reset capturing groups between two match
attempts. Patch by Ma Lin.
..
.. bpo: 35615
.. date: 2018-12-30-20-00-05
.. nonce: Uz1SVh
.. section: Library
:mod:`weakref`: Fix a RuntimeError when copying a WeakKeyDictionary or a
WeakValueDictionary, due to some keys or values disappearing while
iterating.
..
.. bpo: 35606
.. date: 2018-12-29-21-59-03
.. nonce: NjGjou
.. section: Library
Implement :func:`math.prod` as analogous function to :func:`sum` that
returns the product of a 'start' value (default: 1) times an iterable of
numbers. Patch by Pablo Galindo.
..
.. bpo: 32417
.. date: 2018-12-04-13-35-36
.. nonce: _Y9SKM
.. section: Library
Performing arithmetic between :class:`datetime.datetime` subclasses and
:class:`datetime.timedelta` now returns an object of the same type as the
:class:`datetime.datetime` subclass. As a result,
:meth:`datetime.datetime.astimezone` and alternate constructors like
:meth:`datetime.datetime.now` and :meth:`datetime.fromtimestamp` called with
a ``tz`` argument now *also* retain their subclass.
..
.. bpo: 35153
.. date: 2018-11-03-12-38-03
.. nonce: 009pdF
.. section: Library
Add *headers* optional keyword-only parameter to
:class:`xmlrpc.client.ServerProxy`, :class:`xmlrpc.client.Transport` and
:class:`xmlrpc.client.SafeTransport`.  Patch by Cédric Krier.
..
.. bpo: 34572
.. date: 2018-09-05-03-02-32
.. nonce: ayisd2
.. section: Library
Fix C implementation of pickle.loads to use importlib's locking mechanisms,
and thereby avoid using partially loaded modules. Patch by Tim Burgess.
..
.. bpo: 36083
.. date: 2019-02-24-12-40-13
.. nonce: JX7zbv
.. section: Documentation
Fix formatting of --check-hash-based-pycs options in the manpage Synopsis.
..
.. bpo: 36007
.. date: 2019-02-15-15-33-41
.. nonce: OTFrza
.. section: Documentation
Bump minimum sphinx version to 1.8.  Patch by Anthony Sottile.
..
.. bpo: 22062
.. date: 2018-07-28-12-41-01
.. nonce: TaN2hn
.. section: Documentation
Update documentation and docstrings for pathlib. Original patch by Mike
Short.
..
.. bpo: 27313
.. date: 2019-02-24-01-58-38
.. nonce: Sj9veH
.. section: Tests
Avoid test_ttk_guionly ComboboxTest failure with macOS Cocoa Tk.
..
.. bpo: 36019
.. date: 2019-02-21-14-23-51
.. nonce: zS_OUi
.. section: Tests
Add test.support.TEST_HTTP_URL and replace references of
http://www.example.com by this new constant. Contributed by Stéphane Wirtel.
..
.. bpo: 36037
.. date: 2019-02-19-15-21-14
.. nonce: 75wG9_
.. section: Tests
Fix test_ssl for strict OpenSSL configuration like RHEL8 strict crypto
policy. Use older TLS version for minimum TLS version of the server SSL
context if needed, to test TLS version older than default minimum TLS
version.
..
.. bpo: 35798
.. date: 2019-02-16-15-19-31
.. nonce: JF16MP
.. section: Tests
Added :func:`test.support.check_syntax_warning`.
..
.. bpo: 35505
.. date: 2019-02-12-01-33-08
.. nonce: N9ba_K
.. section: Tests
Make test_imap4_host_default_value independent on whether the local IMAP
server is running.
..
.. bpo: 35917
.. date: 2019-02-06-18-06-16
.. nonce: -Clv1L
.. section: Tests
multiprocessing: provide unit tests for SyncManager and SharedMemoryManager
classes + all the shareable types which are supposed to be supported by
them.  (patch by Giampaolo Rodola)
..
.. bpo: 35704
.. date: 2019-01-10-09-14-58
.. nonce: FLglYo
.. section: Tests
Skip ``test_shutil.test_unpack_archive_xztar`` to prevent a MemoryError on
32-bit AIX when MAXDATA setting is less than 0x20000000.
Patch by Michael Felt (aixtools)
..
.. bpo: 34720
.. date: 2018-12-26-12-31-16
.. nonce: T268vz
.. section: Tests
Assert m_state != NULL to mimic GC traversal functions that do not correctly
handle module creation when the module state has not been created.
..
.. bpo: 35976
.. date: 2019-02-11-20-07-43
.. nonce: toap7O
.. section: Windows
Added ARM build support to Windows build files in PCBuild.
..
.. bpo: 35692
.. date: 2019-02-02-16-23-57
.. nonce: cIiiE9
.. section: Windows
``pathlib`` no longer raises when checking file and directory existence on
drives that are not ready
..
.. bpo: 35872
.. date: 2019-02-02-15-57-19
.. nonce: Bba2n7
.. section: Windows
Uses the base Python executable when invoking venv in a virtual environment
..
.. bpo: 35873
.. date: 2019-02-02-15-56-50
.. nonce: UW-qS9
.. section: Windows
Prevents venv paths being inherited by child processes
..
.. bpo: 35299
.. date: 2019-02-02-14-47-12
.. nonce: 1rgEzd
.. section: Windows
Fix sysconfig detection of the source directory and distutils handling of
pyconfig.h during PGO profiling
..
.. bpo: 24310
.. date: 2019-02-23-22-31-20
.. nonce: j_vJQl
.. section: IDLE
IDLE -- Document settings dialog font tab sample.
..
.. bpo: 35833
.. date: 2019-02-08-22-14-24
.. nonce: XKFRvF
.. section: IDLE
Revise IDLE doc for control codes sent to Shell. Add a code example block.
..
.. bpo: 35689
.. date: 2019-01-08-17-51-44
.. nonce: LlaqR8
.. section: IDLE
Add docstrings and unittests for colorizer.py.

.. bpo: 24276
.. date: 9197
.. nonce: awsxJJ
.. release date: 2015-05-24
.. section: Core and Builtins
Fixed optimization of property descriptor getter.
..
.. bpo: 24268
.. date: 9196
.. nonce: nS7uea
.. section: Core and Builtins
PEP 489: Multi-phase extension module initialization. Patch by Petr
Viktorin.
..
.. bpo: 23955
.. date: 9195
.. nonce: hBHSaU
.. section: Core and Builtins
Add pyvenv.cfg option to suppress registry/environment lookup for generating
sys.path on Windows.
..
.. bpo: 24257
.. date: 9194
.. nonce: UBxshR
.. section: Core and Builtins
Fixed system error in the comparison of faked types.SimpleNamespace.
..
.. bpo: 22939
.. date: 9193
.. nonce: DWA9ls
.. section: Core and Builtins
Fixed integer overflow in iterator object.  Patch by Clement Rouault.
..
.. bpo: 23985
.. date: 9192
.. nonce: eezPxO
.. section: Core and Builtins
Fix a possible buffer overrun when deleting a slice from the front of a
bytearray and then appending some other bytes data.
..
.. bpo: 24102
.. date: 9191
.. nonce: 9T6h3m
.. section: Core and Builtins
Fixed exception type checking in standard error handlers.
..
.. bpo: 15027
.. date: 9190
.. nonce: wi9sCd
.. section: Core and Builtins
The UTF-32 encoder is now 3x to 7x faster.
..
.. bpo: 23290
.. date: 9189
.. nonce: 57aqLU
.. section: Core and Builtins
Optimize set_merge() for cases where the target is empty. (Contributed by
Serhiy Storchaka.)
..
.. bpo: 2292
.. date: 9188
.. nonce: h4sibO
.. section: Core and Builtins
PEP 448: Additional Unpacking Generalizations.
..
.. bpo: 24096
.. date: 9187
.. nonce: a_Rap7
.. section: Core and Builtins
Make warnings.warn_explicit more robust against mutation of the
warnings.filters list.
..
.. bpo: 23996
.. date: 9186
.. nonce: znqcT8
.. section: Core and Builtins
Avoid a crash when a delegated generator raises an unnormalized
StopIteration exception.  Patch by Stefan Behnel.
..
.. bpo: 23910
.. date: 9185
.. nonce: _gDzaj
.. section: Core and Builtins
Optimize property() getter calls.  Patch by Joe Jevnik.
..
.. bpo: 23911
.. date: 9184
.. nonce: 0FnTHk
.. section: Core and Builtins
Move path-based importlib bootstrap code to a separate frozen module.
..
.. bpo: 24192
.. date: 9183
.. nonce: 6ZxJ_R
.. section: Core and Builtins
Fix namespace package imports.
..
.. bpo: 24022
.. date: 9182
.. nonce: 1l8YBm
.. section: Core and Builtins
Fix tokenizer crash when processing undecodable source code.
..
.. bpo: 9951
.. date: 9181
.. nonce: wGztNC
.. section: Core and Builtins
Added a hex() method to bytes, bytearray, and memoryview.
..
.. bpo: 22906
.. date: 9180
.. nonce: WN_kQ6
.. section: Core and Builtins
PEP 479: Change StopIteration handling inside generators.
..
.. bpo: 24017
.. date: 9179
.. nonce: QJa1SC
.. section: Core and Builtins
PEP 492: Coroutines with async and await syntax.
..
.. bpo: 14373
.. date: 9178
.. nonce: 0sk6kE
.. section: Library
Added C implementation of functools.lru_cache().  Based on patches by Matt
Joiner and Alexey Kachayev.
..
.. bpo: 24230
.. date: 9177
.. nonce: b-kgme
.. section: Library
The tempfile module now accepts bytes for prefix, suffix and dir parameters
and returns bytes in such situations (matching the os module APIs).
..
.. bpo: 22189
.. date: 9176
.. nonce: 8epgat
.. section: Library
collections.UserString now supports __getnewargs__(), __rmod__(),
casefold(), format_map(), isprintable(), and maketrans(). Patch by Joe
Jevnik.
..
.. bpo: 24244
.. date: 9175
.. nonce: OKE_3R
.. section: Library
Prevents termination when an invalid format string is encountered on Windows
in strftime.
..
.. bpo: 23973
.. date: 9174
.. nonce: EK6awi
.. section: Library
PEP 484: Add the typing module.
..
.. bpo: 23086
.. date: 9173
.. nonce: Aix6Nv
.. section: Library
The collections.abc.Sequence() abstract base class added *start* and *stop*
parameters to the index() mixin. Patch by Devin Jeanpierre.
..
.. bpo: 20035
.. date: 9172
.. nonce: UNZzw6
.. section: Library
Replaced the ``tkinter._fix`` module used for setting up the Tcl/Tk
environment on Windows with a private function in the ``_tkinter`` module
that makes no permanent changes to the environment.
..
.. bpo: 24257
.. date: 9171
.. nonce: L_efq0
.. section: Library
Fixed segmentation fault in sqlite3.Row constructor with faked cursor type.
..
.. bpo: 15836
.. date: 9170
.. nonce: gU3Rmx
.. section: Library
assertRaises(), assertRaisesRegex(), assertWarns() and assertWarnsRegex()
assertments now check the type of the first argument to prevent possible
user error.  Based on patch by Daniel Wagner-Hall.
..
.. bpo: 9858
.. date: 9169
.. nonce: uke9pa
.. section: Library
Add missing method stubs to _io.RawIOBase.  Patch by Laura Rupprecht.
..
.. bpo: 22955
.. date: 9168
.. nonce: Jw_B9_
.. section: Library
attrgetter, itemgetter and methodcaller objects in the operator module now
support pickling.  Added readable and evaluable repr for these objects.
Based on patch by Josh Rosenberg.
..
.. bpo: 22107
.. date: 9167
.. nonce: 2F8k4W
.. section: Library
tempfile.gettempdir() and tempfile.mkdtemp() now try again when a directory
with the chosen name already exists on Windows as well as on Unix.
tempfile.mkstemp() now fails early if parent directory is not valid (not
exists or is a file) on Windows.
..
.. bpo: 23780
.. date: 9166
.. nonce: jFPVcN
.. section: Library
Improved error message in os.path.join() with single argument.
..
.. bpo: 6598
.. date: 9165
.. nonce: JdZNDt
.. section: Library
Increased time precision and random number range in email.utils.make_msgid()
to strengthen the uniqueness of the message ID.
..
.. bpo: 24091
.. date: 9164
.. nonce: Jw0-wj
.. section: Library
Fixed various crashes in corner cases in C implementation of ElementTree.
..
.. bpo: 21931
.. date: 9163
.. nonce: t6lGxY
.. section: Library
msilib.FCICreate() now raises TypeError in the case of a bad argument
instead of a ValueError with a bogus FCI error number. Patch by Jeffrey
Armstrong.
..
.. bpo: 13866
.. date: 9162
.. nonce: n5NAj0
.. section: Library
*quote_via* argument added to urllib.parse.urlencode.
..
.. bpo: 20098
.. date: 9161
.. nonce: Y4otaf
.. section: Library
New mangle_from policy option for email, default True for compat32, but
False for all other policies.
..
.. bpo: 24211
.. date: 9160
.. nonce: j3Afpc
.. section: Library
The email library now supports RFC 6532: it can generate headers using utf-8
instead of encoded words.
..
.. bpo: 16314
.. date: 9159
.. nonce: Xc4d1O
.. section: Library
Added support for the LZMA compression in distutils.
..
.. bpo: 21804
.. date: 9158
.. nonce: lEhTlc
.. section: Library
poplib now supports RFC 6856 (UTF8).
..
.. bpo: 18682
.. date: 9157
.. nonce: 6Pnfte
.. section: Library
Optimized pprint functions for builtin scalar types.
..
.. bpo: 22027
.. date: 9156
.. nonce: _aeUQS
.. section: Library
smtplib now supports RFC 6531 (SMTPUTF8).
..
.. bpo: 23488
.. date: 9155
.. nonce: 7gs3Cm
.. section: Library
Random generator objects now consume 2x less memory on 64-bit.
..
.. bpo: 1322
.. date: 9154
.. nonce: 495nFL
.. section: Library
platform.dist() and platform.linux_distribution() functions are now
deprecated.  Initial patch by Vajrasky Kok.
..
.. bpo: 22486
.. date: 9153
.. nonce: Yxov5m
.. section: Library
Added the math.gcd() function.  The fractions.gcd() function now is
deprecated.  Based on patch by Mark Dickinson.
..
.. bpo: 24064
.. date: 9152
.. nonce: zXC7OL
.. section: Library
Property() docstrings are now writeable. (Patch by Berker Peksag.)
..
.. bpo: 22681
.. date: 9151
.. nonce: 2rIoA2
.. section: Library
Added support for the koi8_t encoding.
..
.. bpo: 22682
.. date: 9150
.. nonce: cP4i3L
.. section: Library
Added support for the kz1048 encoding.
..
.. bpo: 23796
.. date: 9149
.. nonce: JJmUnc
.. section: Library
peek and read1 methods of BufferedReader now raise ValueError if they called
on a closed object. Patch by John Hergenroeder.
..
.. bpo: 21795
.. date: 9148
.. nonce: BDLMS4
.. section: Library
smtpd now supports the 8BITMIME extension whenever the new *decode_data*
constructor argument is set to False.
..
.. bpo: 24155
.. date: 9147
.. nonce: FZx5c2
.. section: Library
optimize heapq.heapify() for better cache performance when heapifying large
lists.
..
.. bpo: 21800
.. date: 9146
.. nonce: evGSKc
.. section: Library
imaplib now supports RFC 5161 (enable), RFC 6855 (utf8/internationalized
email) and automatically encodes non-ASCII usernames and passwords to UTF8.
..
.. bpo: 20274
.. date: 9145
.. nonce: uVHogg
.. section: Library
When calling a _sqlite.Connection, it now complains if passed any keyword
arguments.  Previously it silently ignored them.
..
.. bpo: 20274
.. date: 9144
.. nonce: hBst4M
.. section: Library
Remove ignored and erroneous "kwargs" parameters from three METH_VARARGS
methods on _sqlite.Connection.
..
.. bpo: 24134
.. date: 9143
.. nonce: Ajw0S-
.. section: Library
assertRaises(), assertRaisesRegex(), assertWarns() and assertWarnsRegex()
checks now emits a deprecation warning when callable is None or keyword
arguments except msg is passed in the context manager mode.
..
.. bpo: 24018
.. date: 9142
.. nonce: hk7Rcn
.. section: Library
Add a collections.abc.Generator abstract base class. Contributed by Stefan
Behnel.
..
.. bpo: 23880
.. date: 9141
.. nonce: QtKupC
.. section: Library
Tkinter's getint() and getdouble() now support Tcl_Obj. Tkinter's
getdouble() now supports any numbers (in particular int).
..
.. bpo: 22619
.. date: 9140
.. nonce: 1gJEqV
.. section: Library
Added negative limit support in the traceback module. Based on patch by
Dmitry Kazakov.
..
.. bpo: 24094
.. date: 9139
.. nonce: 7T-u7k
.. section: Library
Fix possible crash in json.encode with poorly behaved dict subclasses.
..
.. bpo: 9246
.. date: 9138
.. nonce: oM-Ikk
.. section: Library
On POSIX, os.getcwd() now supports paths longer than 1025 bytes. Patch
written by William Orr.
..
.. bpo: 17445
.. date: 9137
.. nonce: Z-QYh5
.. section: Library
add difflib.diff_bytes() to support comparison of byte strings (fixes a
regression from Python 2).
..
.. bpo: 23917
.. date: 9136
.. nonce: uMVPV7
.. section: Library
Fall back to sequential compilation when ProcessPoolExecutor doesn't exist.
Patch by Claudiu Popa.
..
.. bpo: 23008
.. date: 9135
.. nonce: OZFCd-
.. section: Library
Fixed resolving attributes with boolean value is False in pydoc.
..
.. bpo: 0
.. date: 9134
.. nonce: 6tJNf2
.. section: Library
Fix asyncio issue 235: LifoQueue and PriorityQueue's put didn't increment
unfinished tasks (this bug was introduced when JoinableQueue was merged with
Queue).
..
.. bpo: 23908
.. date: 9133
.. nonce: ATdNG-
.. section: Library
os functions now reject paths with embedded null character on Windows
instead of silently truncating them.
..
.. bpo: 23728
.. date: 9132
.. nonce: YBmQmV
.. section: Library
binascii.crc_hqx() could return an integer outside of the range 0-0xffff for
empty data.
..
.. bpo: 23887
.. date: 9131
.. nonce: _XpjPN
.. section: Library
urllib.error.HTTPError now has a proper repr() representation. Patch by
Berker Peksag.
..
.. bpo: 0
.. date: 9130
.. nonce: MjNdSC
.. section: Library
asyncio: New event loop APIs: set_task_factory() and get_task_factory().
..
.. bpo: 0
.. date: 9129
.. nonce: rVcHXp
.. section: Library
asyncio: async() function is deprecated in favour of ensure_future().
..
.. bpo: 24178
.. date: 9128
.. nonce: -enO4y
.. section: Library
asyncio.Lock, Condition, Semaphore, and BoundedSemaphore support new 'async
with' syntax.  Contributed by Yury Selivanov.
..
.. bpo: 24179
.. date: 9127
.. nonce: wDy_WZ
.. section: Library
Support 'async for' for asyncio.StreamReader. Contributed by Yury Selivanov.
..
.. bpo: 24184
.. date: 9126
.. nonce: El74TU
.. section: Library
Add AsyncIterator and AsyncIterable ABCs to collections.abc.  Contributed by
Yury Selivanov.
..
.. bpo: 22547
.. date: 9125
.. nonce: _ikCaj
.. section: Library
Implement informative __repr__ for inspect.BoundArguments. Contributed by
Yury Selivanov.
..
.. bpo: 24190
.. date: 9124
.. nonce: 1a3vWW
.. section: Library
Implement inspect.BoundArgument.apply_defaults() method. Contributed by Yury
Selivanov.
..
.. bpo: 20691
.. date: 9123
.. nonce: -raLyf
.. section: Library
Add 'follow_wrapped' argument to inspect.Signature.from_callable() and
inspect.signature(). Contributed by Yury Selivanov.
..
.. bpo: 24248
.. date: 9122
.. nonce: IxWooo
.. section: Library
Deprecate inspect.Signature.from_function() and
inspect.Signature.from_builtin().
..
.. bpo: 23898
.. date: 9121
.. nonce: OSiZie
.. section: Library
Fix inspect.classify_class_attrs() to support attributes with overloaded
__eq__ and __bool__.  Patch by Mike Bayer.
..
.. bpo: 24298
.. date: 9120
.. nonce: u_TaxI
.. section: Library
Fix inspect.signature() to correctly unwrap wrappers around bound methods.
..
.. bpo: 23184
.. date: 9119
.. nonce: G_Cp9v
.. section: IDLE
remove unused names and imports in idlelib. Initial patch by Al Sweigart.
..
.. bpo: 21520
.. date: 9118
.. nonce: FKtvmQ
.. section: Tests
test_zipfile no longer fails if the word 'bad' appears anywhere in the name
of the current directory.
..
.. bpo: 9517
.. date: 9117
.. nonce: W0Ag2V
.. section: Tests
Move script_helper into the support package. Patch by Christie Wilson.
..
.. bpo: 22155
.. date: 9116
.. nonce: 9EbOit
.. section: Documentation
Add File Handlers subsection with createfilehandler to tkinter doc.  Remove
obsolete example from FAQ.  Patch by Martin Panter.
..
.. bpo: 24029
.. date: 9115
.. nonce: M2Bnks
.. section: Documentation
Document the name binding behavior for submodule imports.
..
.. bpo: 24077
.. date: 9114
.. nonce: 2Og2j-
.. section: Documentation
Fix typo in man page for -I command option: -s, not -S
..
.. bpo: 24000
.. date: 9113
.. nonce: MJyXRr
.. section: Tools/Demos
Improved Argument Clinic's mapping of converters to legacy "format units".
Updated the documentation to match.
..
.. bpo: 24001
.. date: 9112
.. nonce: m74vst
.. section: Tools/Demos
Argument Clinic converters now use accept={type} instead of types={'type'}
to specify the types the converter accepts.
..
.. bpo: 23330
.. date: 9111
.. nonce: LTlKDp
.. section: Tools/Demos
h2py now supports arbitrary filenames in #include.
..
.. bpo: 24031
.. date: 9110
.. nonce: duGo88
.. section: Tools/Demos
make patchcheck now supports git checkouts, too.

.. bpo: 32872
.. date: 2018-03-28-01-35-02
.. nonce: J5NDUj
.. release date: 2018-03-28
.. section: Tests
Avoid regrtest compatibility issue with namespace packages.
..
.. bpo: 33163
.. date: 2018-03-28-04-15-03
.. nonce: hfpWuU
.. section: Build
Upgrade pip to 9.0.3 and setuptools to v39.0.1.

.. bpo: 30730
.. date: 9992
.. nonce: rJsyTH
.. original section: Library
.. release date: 2017-07-07
.. section: Security
Prevent environment variables injection in subprocess on Windows.  Prevent
passing other environment variables and command arguments.
..
.. bpo: 30694
.. date: 9991
.. nonce: WkMWM_
.. original section: Library
.. section: Security
Upgrade expat copy from 2.2.0 to 2.2.1 to get fixes of multiple security
vulnerabilities including: :cve:`2017-9233` (External entity infinite loop
DoS), :cve:`2016-9063` (Integer overflow, re-fix), :cve:`2016-0718` (Fix
regression bugs from 2.2.0's fix to :cve:`2016-0718`) and :cve:`2012-0876`
(Counter hash flooding with SipHash). Note: the :cve:`2016-5300` (Use
os-specific entropy sources like getrandom) doesn't impact Python, since
Python already gets entropy from the OS to set the expat secret using
``XML_SetHashSalt()``.
..
.. bpo: 30500
.. date: 9990
.. nonce: 1VG7R-
.. original section: Library
.. section: Security
Fix urllib.parse.splithost() to correctly parse fragments. For example,
``splithost('//127.0.0.1#@evil.com/')`` now correctly returns the
``127.0.0.1`` host, instead of treating ``@evil.com`` as the host in an
authentication (``login@host``).

.. date: 2025-10-14-00-17-48
.. gh-issue: 115119
.. nonce: 470I1N
.. release date: 2025-10-14
.. section: macOS
Update macOS installer to use libmpdecimal 4.0.1.
..
.. date: 2025-10-14-00-08-16
.. gh-issue: 124111
.. nonce: 7-j-DQ
.. section: macOS
Update macOS installer to use Tcl/Tk 9.0.2.
..
.. date: 2025-10-13-23-46-12
.. gh-issue: 132339
.. nonce: kAp603
.. section: macOS
Update macOS installer version of OpenSSL to 3.5.4.
..
.. date: 2025-08-06-06-29-12
.. gh-issue: 137450
.. nonce: JZypb7
.. section: macOS
macOS installer shell path management improvements: separate the installer
``Shell profile updater`` postinstall script from the ``Update Shell
Profile.command`` to enable more robust error handling.
..
.. date: 2025-07-27-02-17-40
.. gh-issue: 137134
.. nonce: pjgITs
.. section: macOS
Update macOS installer to ship with SQLite version 3.50.4.
..
.. date: 2025-10-08-22-54-38
.. gh-issue: 139810
.. nonce: LAaemi
.. section: Windows
Installing with ``py install 3[.x]-dev`` will now select final versions as
well as prereleases.
..
.. date: 2025-10-04-12-18-45
.. gh-issue: 139573
.. nonce: EO9kVB
.. section: Windows
Updated bundled version of OpenSSL to 3.0.18.
..
.. date: 2025-09-15-15-34-29
.. gh-issue: 138896
.. nonce: lkiF_7
.. section: Windows
Fix error installing C runtime on non-updated Windows machines
..
.. date: 2025-09-03-01-07-44
.. gh-issue: 138314
.. nonce: IeWQ2i
.. section: Windows
Add :func:`winreg.DeleteTree`.
..
.. date: 2025-07-27-14-25-11
.. gh-issue: 137136
.. nonce: xNthFT
.. section: Windows
Suppress build warnings when build on Windows with
``--experimental-jit-interpreter``.
..
.. date: 2025-07-27-02-16-53
.. gh-issue: 137134
.. nonce: W0WpDF
.. section: Windows
Update Windows installer to ship with SQLite 3.50.4.
..
.. date: 2025-06-03-18-26-54
.. gh-issue: 135099
.. nonce: Q9usKm
.. section: Windows
Fix a crash that could occur on Windows when a background thread waits on a
:c:type:`PyMutex` while the main thread is shutting down the interpreter.
..
.. date: 2025-05-20-21-43-20
.. gh-issue: 130727
.. nonce: -69t4D
.. section: Windows
Fix a race in internal calls into WMI that can result in an "invalid handle"
exception under high load. Patch by Chris Eibl.
..
.. date: 2025-05-19-03-02-04
.. gh-issue: 76023
.. nonce: vHOf6M
.. section: Windows
Make :func:`os.path.realpath` ignore Windows error 1005 when in non-strict
mode.
..
.. date: 2025-05-13-13-25-27
.. gh-issue: 133779
.. nonce: -YcTBz
.. section: Windows
Reverts the change to generate different :file:`pyconfig.h` files based on
compiler settings, as it was frequently causing extension builds to break.
In particular, the ``Py_GIL_DISABLED`` preprocessor variable must now always
be defined explicitly when compiling for the experimental free-threaded
runtime. The :func:`sysconfig.get_config_var` function can be used to
determine whether the current runtime was compiled with that flag or not.
..
.. date: 2025-05-08-19-07-26
.. gh-issue: 133626
.. nonce: yFTKYK
.. section: Windows
Ensures packages are not accidentally bundled into the traditional
installer.
..
.. date: 2025-05-07-13-04-22
.. gh-issue: 133580
.. nonce: jBMujJ
.. section: Windows
Fix :func:`sys.getwindowsversion` failing without setting an exception when
called on some WinAPI partitions.
..
.. date: 2025-05-07-11-45-30
.. gh-issue: 133572
.. nonce: Xc2zxH
.. section: Windows
Avoid LsaNtStatus to WinError conversion on unsupported WinAPI partitions.
..
.. date: 2025-05-07-11-25-29
.. gh-issue: 133568
.. nonce: oYV0d8
.. section: Windows
Fix compile error when using a WinAPI partition that doesn't support the RPC
runtime library.
..
.. date: 2025-05-07-09-02-19
.. gh-issue: 133562
.. nonce: lqqNW1
.. section: Windows
Disable handling of security descriptors by :func:`os.mkdir` with mode
``0o700`` on WinAPI partitions that do not support it. This only affects
custom builds for specialized targets.
..
.. date: 2025-05-07-08-19-15
.. gh-issue: 133537
.. nonce: yzf963
.. section: Windows
Avoid using console I/O in WinAPI partitions that don’t support it
..
.. date: 2025-03-31-15-37-57
.. gh-issue: 131942
.. nonce: jip_aL
.. section: Windows
Use the Python-specific :c:macro:`Py_DEBUG` macro rather than
:c:macro:`!_DEBUG` in Windows-related C code. Patch by Xuehai Pan.
..
.. date: 2025-09-25-10-31-02
.. gh-issue: 139330
.. nonce: 5WWkY0
.. section: Tools/Demos
SBOM generation tool didn't cross-check the version and checksum values
against the ``Modules/expat/refresh.sh`` script, leading to the values
becoming out-of-date during routine updates.
..
.. date: 2025-08-28-06-22-26
.. gh-issue: 132006
.. nonce: eZQmc6
.. section: Tools/Demos
XCframeworks now include privacy manifests to satisfy Apple App Store
submission requirements.
..
.. date: 2025-08-27-11-14-53
.. gh-issue: 138171
.. nonce: Suz8ob
.. section: Tools/Demos
A script for building an iOS XCframework was added. As part of this change,
the top level ``iOS`` folder has been moved to be a subdirectory of the
``Apple`` folder.
..
.. date: 2025-08-21-14-04-50
.. gh-issue: 137873
.. nonce: qxffLt
.. section: Tools/Demos
The iOS test runner has been simplified, resolving some issues that have
been observed using the runner in GitHub Actions and Azure Pipelines test
environments.
..
.. date: 2025-08-06-11-54-55
.. gh-issue: 137484
.. nonce: 8iFAQs
.. section: Tools/Demos
Have ``Tools/wasm/wasi`` put the build Python into a directory named after
the build triple instead of "build".
..
.. date: 2025-08-01-13-27-43
.. gh-issue: 137025
.. nonce: ubuhQC
.. section: Tools/Demos
The ``wasm_build.py`` script has been removed.  ``Tools/wasm/emscripten``
and ``Tools/wasm/wasi`` should be used instead, as described in the `Dev
Guide <https://devguide.python.org/contrib/workflows/compile/>`__.
..
.. date: 2025-07-30-11-15-47
.. gh-issue: 137248
.. nonce: 8IxwY3
.. section: Tools/Demos
Add a ``--logdir`` option to ``Tools/wasm/wasi`` for specifying where to
write log files.
..
.. date: 2025-07-30-10-28-35
.. gh-issue: 137243
.. nonce: NkdUqH
.. section: Tools/Demos
Have Tools/wasm/wasi detect a WASI SDK install in /opt when it was directly
extracted from a release tarball.
..
.. date: 2025-07-05-15-10-42
.. gh-issue: 136251
.. nonce: GRM6o8
.. section: Tools/Demos
Fixes and usability improvements for ``Tools/wasm/emscripten/web_example``
..
.. date: 2025-06-26-15-58-13
.. gh-issue: 135968
.. nonce: C4v_-W
.. section: Tools/Demos
Stubs for ``strip`` are now provided as part of an iOS install.
..
.. date: 2025-06-11-12-14-06
.. gh-issue: 135379
.. nonce: 25ttXq
.. section: Tools/Demos
The cases generator no longer accepts type annotations on stack items.
Conversions to non-default types are now done explicitly in bytecodes.c and
optimizer_bytecodes.c. This will simplify code generation for top-of-stack
caching and other future features.
..
.. date: 2025-05-19-14-57-46
.. gh-issue: 134215
.. nonce: sbdDK6
.. section: Tools/Demos
:term:`REPL` import autocomplete only suggests private modules when
explicitly specified.
..
.. date: 2025-09-22-15-40-09
.. gh-issue: 139208
.. nonce: Tc13dl
.. section: Tests
Fix regrtest ``--fast-ci --verbose``: don't ignore the ``--verbose`` option
anymore. Patch by Victor Stinner.
..
.. date: 2025-09-21-16-00-30
.. gh-issue: 138313
.. nonce: lBx2en
.. section: Tests
Restore skipped test and add janky workaround to prevent select buildbots
from failing with a ResourceWarning.
..
.. date: 2025-06-26-15-15-35
.. gh-issue: 135966
.. nonce: EBpF8Y
.. section: Tests
The iOS testbed now handles the ``app_packages`` folder as a site directory.
..
.. date: 2025-06-19-15-29-38
.. gh-issue: 135494
.. nonce: FVl9a0
.. section: Tests
Fix regrtest to support excluding tests from ``--pgo`` tests. Patch by
Victor Stinner.
..
.. date: 2025-06-17-08-48-08
.. gh-issue: 132815
.. nonce: CY1Esu
.. section: Tests
Fix test__opcode: add ``JUMP_BACKWARD`` to specialization stats.
..
.. date: 2025-06-14-13-20-17
.. gh-issue: 135489
.. nonce: Uh0yVO
.. section: Tests
Show verbose output for failing tests during PGO profiling step with
--enable-optimizations.
..
.. date: 2025-06-11-16-52-49
.. gh-issue: 135401
.. nonce: ccMXmL
.. section: Tests
Add a new GitHub CI job to test the :mod:`ssl` module with `AWS-LC
<https://github.com/aws/aws-lc>`_ as the backing cryptography and TLS
library.
..
.. date: 2025-06-04-13-07-44
.. gh-issue: 135120
.. nonce: NapnZT
.. section: Tests
Add :func:`!test.support.subTests`.
..
.. date: 2025-05-23-09-19-52
.. gh-issue: 134567
.. nonce: hwEIMb
.. section: Tests
Expose log formatter to users in TestCase.assertLogs.
:func:`unittest.TestCase.assertLogs` will now optionally accept a formatter
that will be used to format the strings in output if provided.
..
.. date: 2025-05-09-14-54-48
.. gh-issue: 133744
.. nonce: LCquu0
.. section: Tests
Fix multiprocessing interrupt test. Add an event to synchronize the parent
process with the child process: wait until the child process starts
sleeping. Patch by Victor Stinner.
..
.. date: 2025-05-09-04-11-06
.. gh-issue: 133682
.. nonce: -_lwo3
.. section: Tests
Fixed test case ``test.test_annotationlib.TestStringFormat.test_displays``
which ensures proper handling of complex data structures (lists, sets,
dictionaries, and tuples) in string annotations.
..
.. date: 2025-05-08-15-06-01
.. gh-issue: 133639
.. nonce: 50-kbV
.. section: Tests
Fix ``TestPyReplAutoindent.test_auto_indent_default()`` doesn't run
``input_code``.
..
.. date: 2025-10-07-19-31-34
.. gh-issue: 139700
.. nonce: vNHU1O
.. section: Security
Check consistency of the zip64 end of central directory record. Support
records with "zip64 extensible data" if there are no bytes prepended to the
ZIP file.
..
.. date: 2025-09-29-00-01-28
.. gh-issue: 139400
.. nonce: X2T-jO
.. section: Security
:mod:`xml.parsers.expat`: Make sure that parent Expat parsers are only
garbage-collected once they are no longer referenced by subparsers created
by :meth:`~xml.parsers.expat.xmlparser.ExternalEntityParserCreate`. Patch by
Sebastian Pipping.
..
.. date: 2025-09-24-13-39-56
.. gh-issue: 139283
.. nonce: jODz_q
.. section: Security
:mod:`sqlite3`: correctly handle maximum number of rows to fetch in
:meth:`Cursor.fetchmany <sqlite3.Cursor.fetchmany>` and reject negative
values for :attr:`Cursor.arraysize <sqlite3.Cursor.arraysize>`. Patch by
Bénédikt Tran.
..
.. date: 2025-06-27-21-23-19
.. gh-issue: 136053
.. nonce: QZxcee
.. section: Security
:mod:`marshal`: fix a possible crash when deserializing :class:`slice`
objects.
..
.. date: 2025-06-25-14-13-39
.. gh-issue: 135661
.. nonce: idjQ0B
.. section: Security
Fix parsing start and end tags in :class:`html.parser.HTMLParser` according
to the HTML5 standard.
* Whitespaces no longer accepted between ``</`` and the tag name.
E.g. ``</ script>`` does not end the script section.
* Vertical tabulation (``\v``) and non-ASCII whitespaces no longer recognized
as whitespaces. The only whitespaces are ``\t\n\r\f`` and space.
* Null character (U+0000) no longer ends the tag name.
* Attributes and slashes after the tag name in end tags are now ignored,
instead of terminating after the first ``>`` in quoted attribute value.
E.g. ``</script/foo=">"/>``.
* Multiple slashes and whitespaces between the last attribute and closing ``>``
are now ignored in both start and end tags. E.g. ``<a foo=bar/ //>``.
* Multiple ``=`` between attribute name and value are no longer collapsed.
E.g. ``<a foo==bar>`` produces attribute "foo" with value "=bar".
..
.. date: 2025-06-18-13-34-55
.. gh-issue: 135661
.. nonce: NZlpWf
.. section: Security
Fix CDATA section parsing in :class:`html.parser.HTMLParser` according to
the HTML5 standard: ``] ]>`` and ``]] >`` no longer end the CDATA section.
Add private method ``_set_support_cdata()`` which can be used to specify how
to parse ``<[CDATA[`` --- as a CDATA section in foreign content (SVG or
MathML) or as a bogus comment in the HTML namespace.
..
.. date: 2025-06-18-13-28-08
.. gh-issue: 102555
.. nonce: nADrzJ
.. section: Security
Fix comment parsing in :class:`html.parser.HTMLParser` according to the
HTML5 standard. ``--!>`` now ends the comment. ``-- >`` no longer ends the
comment. Support abnormally ended empty comments ``<-->`` and ``<--->``.
..
.. date: 2025-06-13-15-55-22
.. gh-issue: 135462
.. nonce: KBeJpc
.. section: Security
Fix quadratic complexity in processing specially crafted input in
:class:`html.parser.HTMLParser`. End-of-file errors are now handled
according to the HTML5 specs -- comments and declarations are automatically
closed, tags are ignored.
..
.. date: 2025-06-09-20-38-25
.. gh-issue: 118350
.. nonce: KgWCcP
.. section: Security
Fix support of escapable raw text mode (elements "textarea" and "title") in
:class:`html.parser.HTMLParser`.
..
.. date: 2025-06-02-11-32-23
.. gh-issue: 135034
.. nonce: RLGjbp
.. section: Security
Fixes multiple issues that allowed ``tarfile`` extraction filters
(``filter="data"`` and ``filter="tar"``) to be bypassed using crafted
symlinks and hard links.
Addresses :cve:`2024-12718`, :cve:`2025-4138`, :cve:`2025-4330`, and
:cve:`2025-4517`.
..
.. date: 2025-05-09-20-22-54
.. gh-issue: 133767
.. nonce: kN2i3Q
.. section: Security
Fix use-after-free in the "unicode-escape" decoder with a non-"strict" error
handler.
..
.. date: 2025-05-07-22-49-27
.. gh-issue: 133623
.. nonce: fgWkBm
.. section: Security
Indicate through :data:`ssl.HAS_PSK_TLS13` whether the :mod:`ssl` module
supports "External PSKs" in TLSv1.3, as described in RFC 9258. Patch by Will
Childs-Klein.
..
.. date: 2025-01-14-11-19-07
.. gh-issue: 128840
.. nonce: M1doZW
.. section: Security
Short-circuit the processing of long IPv6 addresses early in
:mod:`ipaddress` to prevent excessive memory consumption and a minor
denial-of-service.
..
.. date: 2025-10-11-20-03-13
.. gh-issue: 139482
.. nonce: du2Stg
.. section: Library
Optimize :data:`os.environ.clear() <os.environ>` by calling
:manpage:`clearenv(3)` when this function is available. Patch by Victor
Stinner.
..
.. date: 2025-10-11-17-41-26
.. gh-issue: 139958
.. nonce: AnCakj
.. section: Library
The ``application/toml`` mime type is now supported by :mod:`mimetypes`.
Patch by Gil Forcada.
..
.. date: 2025-10-11-14-37-42
.. gh-issue: 139823
.. nonce: uGF4oh
.. section: Library
:mod:`ensurepip` now fails with a nicer error message when the :mod:`zlib`
module is not available.
..
.. date: 2025-10-11-10-02-56
.. gh-issue: 139905
.. nonce: UyJIR_
.. section: Library
Add suggestion to error message for :class:`typing.Generic` subclasses when
``cls.__parameters__`` is missing due to a parent class failing to call
:meth:`super().__init_subclass__() <object.__init_subclass__>` in its
``__init_subclass__``.
..
.. date: 2025-10-10-11-22-50
.. gh-issue: 139894
.. nonce: ECAXqj
.. section: Library
Fix incorrect sharing of current task with the child process while forking
in :mod:`asyncio`. Patch by Kumar Aditya.
..
.. date: 2025-10-09-21-37-20
.. gh-issue: 139845
.. nonce: dzx5UP
.. section: Library
Fix to not print KeyboardInterrupt twice in default asyncio REPL.
..
.. date: 2025-10-09-13-48-28
.. gh-issue: 139783
.. nonce: __NUgo
.. section: Library
Fix :func:`inspect.getsourcelines` for the case when a decorator is followed
by a comment or an empty line.
..
.. date: 2025-10-09-03-06-19
.. gh-issue: 139809
.. nonce: lzHJNu
.. section: Library
Prevent premature colorization of subparser ``prog`` in
:meth:`argparse.ArgumentParser.add_subparsers` to respect color environment
variable changes after parser creation.
..
.. date: 2025-10-08-00-06-30
.. gh-issue: 139736
.. nonce: baPeBd
.. section: Library
Fix excessive indentation in the default :mod:`argparse`
:class:`!HelpFormatter`. Patch by Alexander Edland.
..
.. date: 2025-10-02-17-40-10
.. gh-issue: 70765
.. nonce: zVlLZn
.. section: Library
:mod:`http.server`: fix default handling of HTTP/0.9 requests in
:class:`~http.server.BaseHTTPRequestHandler`. Previously,
:meth:`!BaseHTTPRequestHandler.parse_request` incorrectly waited for headers
in the request although those are not supported in HTTP/0.9. Patch by
Bénédikt Tran.
..
.. date: 2025-10-02-15-45-08
.. gh-issue: 139322
.. nonce: rouPGj
.. section: Library
Fix :func:`os.getlogin` error handling: fix the error number. Patch by
Victor Stinner.
..
.. date: 2025-10-01-20-30-03
.. gh-issue: 135953
.. nonce: NAofJl
.. section: Library
Add a Gecko format output to the tachyon profiler via ``--gecko``.
..
.. date: 2025-09-29-14-15-20
.. gh-issue: 139184
.. nonce: dNl9O4
.. section: Library
:func:`os.forkpty` does now make the returned file descriptor
non-inheritable.
..
.. date: 2025-09-28-16-34-11
.. gh-issue: 139391
.. nonce: nRFnmx
.. section: Library
Fix an issue when, on non-Windows platforms, it was not possible to
gracefully exit a ``python -m asyncio`` process suspended by Ctrl+Z and
later resumed by :manpage:`fg` other than with :manpage:`kill`.
..
.. date: 2025-09-27-08-26-31
.. gh-issue: 139374
.. nonce: hfh-dl
.. section: Library
:mod:`timeit`: Add color to error tracebacks.
..
.. date: 2025-09-26-18-04-28
.. gh-issue: 90949
.. nonce: YHjSzX
.. section: Library
Add
:meth:`~xml.parsers.expat.xmlparser.SetBillionLaughsAttackProtectionActivationThreshold`
and
:meth:`~xml.parsers.expat.xmlparser.SetBillionLaughsAttackProtectionMaximumAmplification`
to :ref:`xmlparser <xmlparser-objects>` objects to tune protections against
`billion laughs <https://en.wikipedia.org/wiki/Billion_laughs_attack>`_
attacks. Patch by Bénédikt Tran.
..
.. date: 2025-09-25-07-33-43
.. gh-issue: 139312
.. nonce: ygE8AC
.. section: Library
Upgrade bundled libexpat to 2.7.3
..
.. date: 2025-09-24-14-17-34
.. gh-issue: 139289
.. nonce: Vmk25k
.. section: Library
Do a real lazy-import on :mod:`rlcompleter` in :mod:`pdb` and restore the
existing completer after importing :mod:`rlcompleter`.
..
.. date: 2025-09-22-14-40-11
.. gh-issue: 90949
.. nonce: UM35nb
.. section: Library
Add :meth:`~xml.parsers.expat.xmlparser.SetAllocTrackerActivationThreshold`
and :meth:`~xml.parsers.expat.xmlparser.SetAllocTrackerMaximumAmplification`
to :ref:`xmlparser <xmlparser-objects>` objects to tune protections against
disproportional amounts of dynamic memory usage from within an Expat parser.
Patch by Bénédikt Tran.
..
.. date: 2025-09-22-11-30-45
.. gh-issue: 67795
.. nonce: fROoZt
.. section: Library
Functions that take timestamp or timeout arguments now accept any real
numbers (such as :class:`~decimal.Decimal` and
:class:`~fractions.Fraction`), not only integers or floats, although this
does not improve precision.
..
.. date: 2025-09-22-11-19-05
.. gh-issue: 95953
.. nonce: 7oLoag
.. section: Library
A CSS class, ``diff_changed``, was added to the changed lines in the
``make_table`` output of :class:`difflib.HtmlDiff`. Patch by Katie Gardner.
..
.. date: 2025-09-21-15-58-57
.. gh-issue: 139210
.. nonce: HGbMvz
.. section: Library
Fix use-after-free when reporting unknown event in
:func:`xml.etree.ElementTree.iterparse`. Patch by Ken Jin.
..
.. date: 2025-09-20-17-50-31
.. gh-issue: 138860
.. nonce: Y9JXap
.. section: Library
Lazy import :mod:`rlcompleter` in :mod:`pdb` to avoid deadlock in
subprocess.
..
.. date: 2025-09-19-09-36-42
.. gh-issue: 112729
.. nonce: mmty0_
.. section: Library
Fix crash when calling :func:`concurrent.interpreters.create` when the
process is out of memory.
..
.. date: 2025-09-19-07-41-52
.. gh-issue: 126016
.. nonce: Uz9W6h
.. section: Library
Fix an assertion failure when sending :exc:`KeyboardInterrupt` to a Python
process running a subinterpreter in a separate thread.
..
.. date: 2025-09-18-14-21-57
.. gh-issue: 118803
.. nonce: 2JPbto
.. section: Library
:class:`collections.abc.ByteString` has been removed from
``collections.abc.__all__``, and :class:`typing.ByteString` has been removed
from ``typing.__all__``. The former has been deprecated since Python 3.12,
and the latter has been deprecated since Python 3.9. Both classes are
scheduled for removal in Python 3.17.
Additionally, the following statements now cause ``DeprecationWarning``\ s
to be emitted at runtime: ``from collections.abc import ByteString``, ``from
typing import ByteString``, ``import collections.abc;
collections.abc.ByteString`` and ``import typing; typing.ByteString``. Both
classes already caused ``DeprecationWarning``\ s to be emitted if they were
subclassed or used as the second argument to ``isinstance()`` or
``issubclass()``, but they did not previously lead to
``DeprecationWarning``\ s if they were merely imported or accessed from
their respective modules.
..
.. date: 2025-09-18-05-32-18
.. gh-issue: 135729
.. nonce: 8AmMza
.. section: Library
Fix unraisable exception during finalization when using
:mod:`concurrent.interpreters` in the REPL.
..
.. date: 2025-09-17-21-54-53
.. gh-issue: 139076
.. nonce: 2eX9lG
.. section: Library
Fix a bug in the :mod:`pydoc` module that was hiding functions in a Python
module if they were implemented in an extension module and the module did
not have ``__all__``.
..
.. date: 2025-09-17-21-52-30
.. gh-issue: 139090
.. nonce: W7vbhF
.. section: Library
Add :data:`os.RWF_DONTCACHE` constant for Linux 6.14+.
..
.. date: 2025-09-17-19-08-34
.. gh-issue: 139065
.. nonce: Hu8fM5
.. section: Library
Fix trailing space before a wrapped long word if the line length is exactly
*width* in :mod:`textwrap`.
..
.. date: 2025-09-17-12-07-21
.. gh-issue: 139001
.. nonce: O6tseN
.. section: Library
Fix race condition in :class:`pathlib.Path` on the internal ``_raw_paths``
field.
..
.. date: 2025-09-17-08-32-43
.. gh-issue: 138813
.. nonce: LHkHjX
.. section: Library
:class:`!multiprocessing.BaseProcess` defaults ``kwargs`` to ``None``
instead of a shared dictionary.
..
.. date: 2025-09-16-19-05-29
.. gh-issue: 138998
.. nonce: URl0Y_
.. section: Library
Update bundled libexpat to 2.7.2
..
.. date: 2025-09-16-16-46-58
.. gh-issue: 138993
.. nonce: -8s8_T
.. section: Library
Dedent :data:`credits` text.
..
.. date: 2025-09-16-15-56-29
.. gh-issue: 118803
.. nonce: aOPtmL
.. section: Library
Add back :class:`collections.abc.ByteString` and :class:`typing.ByteString`.
Both had been removed in prior alpha, beta and release candidates for Python
3.14, but their removal has now been postponed to Python 3.17.
..
.. date: 2025-09-15-19-29-12
.. gh-issue: 130567
.. nonce: shDEnT
.. section: Library
Fix possible crash in :func:`locale.strxfrm` due to a platform bug on macOS.
..
.. date: 2025-09-15-13-09-19
.. gh-issue: 137226
.. nonce: HH3_ik
.. section: Library
Fix :func:`typing.get_type_hints` calls on generic :class:`typing.TypedDict`
classes defined with string annotations.
..
.. date: 2025-09-15-08-57-39
.. gh-issue: 138899
.. nonce: Uh6fvY
.. section: Library
Executing ``quit`` command in :mod:`pdb` will raise :exc:`bdb.BdbQuit` when
:mod:`pdb` is started from an asyncio console using :func:`breakpoint` or
:func:`pdb.set_trace`.
..
.. date: 2025-09-12-01-01-05
.. gh-issue: 138804
.. nonce: 46ZukT
.. section: Library
Raise :exc:`TypeError` instead of :exc:`AttributeError` when an argument of
incorrect type is passed to :func:`shlex.quote`. This restores the behavior
of the function prior to 3.14.
..
.. date: 2025-09-11-11-09-28
.. gh-issue: 138779
.. nonce: TNZnLr
.. section: Library
Support device numbers larger than ``2**63-1`` for the
:attr:`~os.stat_result.st_rdev` field of the :class:`os.stat_result`
structure.
..
.. date: 2025-09-10-13-32-25
.. gh-issue: 138682
.. nonce: iExqx1
.. section: Library
Added symmetric difference support to :class:`collections.Counter` objects.
..
.. date: 2025-09-10-10-11-59
.. gh-issue: 138712
.. nonce: avrPG5
.. section: Library
Add :const:`os.NODEV`.
..
.. date: 2025-09-10-10-02-59
.. gh-issue: 128636
.. nonce: ldRKGZ
.. section: Library
Fix crash in PyREPL when os.environ is overwritten with an invalid value for
mac
..
.. date: 2025-09-09-17-57-49
.. gh-issue: 138720
.. nonce: hAtsm-
.. section: Library
Fix an issue where :class:`io.BufferedWriter` and :class:`io.BufferedRandom`
had different definitions of "closed" for :meth:`~io.IOBase.close` and
:meth:`~io.IOBase.flush` which resulted in an exception when close called
flush but flush thought the file was already closed.
..
.. date: 2025-09-09-10-48-26
.. gh-issue: 138706
.. nonce: xB--LX
.. section: Library
Update :mod:`unicodedata` database to Unicode 17.0.0.
..
.. date: 2025-09-08-17-32-02
.. gh-issue: 76007
.. nonce: peEgcr
.. section: Library
Deprecate ``__version__`` from a number of standard library modules. Patch
by Hugo van Kemenade.
..
.. date: 2025-09-06-20-09-32
.. gh-issue: 138535
.. nonce: mlntEe
.. section: Library
Speed up :func:`os.stat` for files with reasonable timestamps. Contributed
by Jeffrey Bosboom.
..
.. date: 2025-09-06-14-56-40
.. gh-issue: 116946
.. nonce: GGIeyO
.. section: Library
:mod:`curses.panel`: the type of :func:`curses.panel.new_panel` is now
immutable. Patch by Bénédikt Tran.
..
.. date: 2025-09-06-14-54-01
.. gh-issue: 116946
.. nonce: hzQEWI
.. section: Library
:mod:`zlib`: the types of :func:`zlib.compressobj` and
:func:`zlib.decompressobj` are now immutable. Patch by Bénédikt Tran.
..
.. date: 2025-09-06-14-53-19
.. gh-issue: 116946
.. nonce: c-npxd
.. section: Library
:mod:`os`: the :class:`os.DirEntry` type and the type of :func:`os.scandir`
are now immutable. Patch by Bénédikt Tran.
..
.. date: 2025-09-06-14-47-23
.. gh-issue: 116946
.. nonce: hj_u1t
.. section: Library
:mod:`tkinter`: the types :class:`!_tkinter.Tcl_Obj` (wrapper for Tcl
objects), :class:`!_tkinter.tktimertoken` (obtained by calling
``createtimerhandler()`` on a :attr:`Tk <tkinter.Tk.tk>` application) and
:class:`!_tkinter.tkapp` (the runtime type of Tk applications) are now
immutable. Patch by Bénédikt Tran.
..
.. date: 2025-09-06-11-26-21
.. gh-issue: 138514
.. nonce: 66ltOb
.. section: Library
Raise :exc:`ValueError` when a multi-character string is passed to the
*echo_char* parameter of :func:`getpass.getpass`. Patch by Benjamin Johnson.
..
.. date: 2025-09-05-21-10-24
.. gh-issue: 137706
.. nonce: 0EztiJ
.. section: Library
Fix the partial evaluation of annotations that use ``typing.Annotated[T,
x]`` where ``T`` is a forward reference.
..
.. date: 2025-09-05-15-35-59
.. gh-issue: 88375
.. nonce: dC491a
.. section: Library
Fix normalization of the ``robots.txt`` rules and URLs in the
:mod:`urllib.robotparser` module. No longer ignore trailing ``?``.
Distinguish raw special characters ``?``, ``=`` and ``&`` from the
percent-encoded ones.
..
.. date: 2025-09-05-07-50-18
.. gh-issue: 138515
.. nonce: E3M-pu
.. section: Library
:mod:`email` is added to Emscripten build.
..
.. date: 2025-09-05-05-53-43
.. gh-issue: 99948
.. nonce: KMSlG6
.. section: Library
:func:`ctypes.util.find_library` now works in Emscripten build.
..
.. date: 2025-09-04-15-18-11
.. gh-issue: 111788
.. nonce: tuTEM5
.. section: Library
Fix parsing errors in the :mod:`urllib.robotparser` module. Don't fail
trying to parse weird paths. Don't fail trying to decode non-UTF-8
``robots.txt`` files.
..
.. date: 2025-09-03-15-20-10
.. gh-issue: 138432
.. nonce: RMc7UX
.. section: Library
:meth:`zoneinfo.reset_tzpath` will now convert any :class:`os.PathLike`
objects it receives into strings before adding them to ``TZPATH``. It will
raise ``TypeError`` if anything other than a string is found after this
conversion. If given an :class:`os.PathLike` object that represents a
relative path, it will now raise ``ValueError`` instead of ``TypeError``,
and present a more informative error message.
..
.. date: 2025-09-03-09-03-11
.. gh-issue: 132657
.. nonce: cbAIDh
.. section: Library
Improve the scaling of :func:`copy.copy` and :func:`copy.deepcopy` in the
free-threading build.
..
.. date: 2025-09-02-10-27-21
.. gh-issue: 116946
.. nonce: VxXNGD
.. section: Library
The types of :func:`select.poll` and :func:`select.epoll` objects are now
immutable. Patch by Bénédikt Tran.
..
.. date: 2025-09-02-10-23-09
.. gh-issue: 116946
.. nonce: U6RpwK
.. section: Library
The :class:`!_random.Random` C type is now immutable. Patch by Bénédikt
Tran.
..
.. date: 2025-08-31-22-10-22
.. gh-issue: 57911
.. nonce: N_Ixtv
.. section: Library
When extracting tar files on Windows, slashes in symlink targets will be
replaced by backslashes to prevent corrupted links.
..
.. date: 2025-08-31-12-34-02
.. gh-issue: 138205
.. nonce: iHXb1z
.. section: Library
Removed the :meth:`~mmap.mmap.resize` method on platforms that don't support
the underlying syscall, instead of raising a :exc:`SystemError`.
..
.. date: 2025-08-31-09-06-49
.. gh-issue: 138008
.. nonce: heOvsU
.. section: Library
Fix segmentation faults in the :mod:`ctypes` module due to invalid
:attr:`~ctypes._CFuncPtr.argtypes`. Patch by Dung Nguyen.
..
.. date: 2025-08-30-17-58-04
.. gh-issue: 138252
.. nonce: CDiEby
.. section: Library
:mod:`ssl`: :class:`~ssl.SSLContext` objects can now set client and server
TLS signature algorithms. If Python has been built with OpenSSL 3.5 or
later, :class:`~ssl.SSLSocket` objects can return the signature algorithms
selected on a connection.
..
.. date: 2025-08-30-10-58-15
.. gh-issue: 138253
.. nonce: 9Ehj-N
.. section: Library
Add the *block* parameter in the :meth:`!put` and :meth:`!get` methods of
the :mod:`concurrent.interpreters` queues for compatibility with the
:class:`queue.Queue` interface.
..
.. date: 2025-08-30-10-04-28
.. gh-issue: 60462
.. nonce: yh_vDc
.. section: Library
Fix :func:`locale.strxfrm` on Solaris (and possibly other platforms).
..
.. date: 2025-08-29-12-56-55
.. gh-issue: 138239
.. nonce: uthZFI
.. section: Library
The REPL now highlights :keyword:`type` as a soft keyword in :ref:`type
statements <type>`.
..
.. date: 2025-08-29-12-05-33
.. gh-issue: 78502
.. nonce: VpIMxg
.. section: Library
:class:`mmap.mmap` now has a *trackfd* parameter on Windows; if it is
``False``, the file handle corresponding to *fileno* will not be duplicated.
..
.. date: 2025-08-28-13-20-09
.. gh-issue: 138204
.. nonce: 8oLOud
.. section: Library
Forbid expansion of shared anonymous :mod:`memory maps <mmap>` on Linux,
which caused a bus error.
..
.. date: 2025-08-27-17-05-36
.. gh-issue: 138010
.. nonce: ZZJmPL
.. section: Library
Fix an issue where defining a class with a
:deco:`warnings.deprecated`-decorated base class may not invoke the correct
:meth:`~object.__init_subclass__` method in cases involving multiple
inheritance. Patch by Brian Schubert.
..
.. date: 2025-08-25-22-38-03
.. gh-issue: 134716
.. nonce: kyYKeX
.. section: Library
Add support of regular expressions in the :option:`-W` option and the
:envvar:`PYTHONWARNINGS` environment variable.
..
.. date: 2025-08-25-18-06-04
.. gh-issue: 138133
.. nonce: Zh9rGo
.. section: Library
Prevent infinite traceback loop when sending CTRL^C to Python through
``strace``.
..
.. date: 2025-08-25-16-22-32
.. gh-issue: 138122
.. nonce: eMNDZ1
.. section: Library
Implement :pep:`799` -- A dedicated profiling package for organizing Python
profiling tools. Patch by Pablo Galindo.
..
.. date: 2025-08-24-02-04-32
.. gh-issue: 138092
.. nonce: V4-wTO
.. section: Library
Fixed a bug in :meth:`mmap.mmap.flush` where calling with only an offset
parameter would fail.
..
.. date: 2025-08-22-12-48-14
.. gh-issue: 138044
.. nonce: lEQULC
.. section: Library
Remove compatibility shim for deprecated parameter *package* in
:func:`importlib.resources.files`. Patch by Semyon Moroz.
..
.. date: 2025-08-22-09-53-45
.. gh-issue: 86819
.. nonce: ECxvwx
.. section: Library
:mod:`socket`: Add missing constants for ISO-TP sockets.
..
.. date: 2025-08-19-00-12-57
.. gh-issue: 137884
.. nonce: 4faCA_
.. section: Library
Add :func:`threading.get_native_id` support for Illumos/Solaris. Patch by
Yüce Tekol.
..
.. date: 2025-08-18-16-02-51
.. gh-issue: 134869
.. nonce: GnAjnU
.. section: Library
Fix an issue where pressing Ctrl+C during tab completion in the REPL would
leave the autocompletion menu in a corrupted state.
..
.. date: 2025-08-18-07-10-55
.. gh-issue: 137840
.. nonce: 9b7AnG
.. section: Library
:class:`typing.TypedDict` now supports the ``closed`` and ``extra_items``
keyword arguments (as described in :pep:`728`) to control whether additional
non-required keys are allowed and to specify their value type.
..
.. date: 2025-08-17-10-22-31
.. gh-issue: 132947
.. nonce: XR4MJ8
.. section: Library
Applied changes to ``importlib.metadata`` from `importlib_metadata 8.7
<https://importlib-metadata.readthedocs.io/en/latest/history.html#v8-7-0>`_,
including ``dist`` now disallowed for ``EntryPoints.select``; deferred
imports for faster import times; added support for metadata with newlines
(python/cpython#119650); and ``metadata()`` function now returns ``None``
when a metadata directory is present but no metadata is present.
..
.. date: 2025-08-16-18-11-41
.. gh-issue: 90548
.. nonce: q3aJUK
.. section: Library
Fix ``musl`` detection for :func:`platform.libc_ver` on Alpine Linux if
compiled with --strip-all.
..
.. date: 2025-08-16-16-04-15
.. gh-issue: 137317
.. nonce: Dl13B5
.. section: Library
:func:`inspect.signature` now correctly handles classes that use a
descriptor on a wrapped :meth:`!__init__` or :meth:`!__new__` method.
Contributed by Yongyu Yan.
..
.. date: 2025-08-16-09-02-11
.. gh-issue: 137754
.. nonce: mCev1Y
.. section: Library
Fix import of the :mod:`zoneinfo` module if the C implementation of the
:mod:`datetime` module is not available.
..
.. date: 2025-08-14-10-27-07
.. gh-issue: 125854
.. nonce: vDzFcZ
.. section: Library
Improve error messages for invalid category in :func:`warnings.warn`.
..
.. date: 2025-08-14-00-00-12
.. gh-issue: 137729
.. nonce: i9NSKP
.. section: Library
:func:`locale.setlocale` now supports language codes with ``@``-modifiers.
``@``-modifier are no longer silently removed in :func:`locale.getlocale`,
but included in the language code.
..
.. date: 2025-08-13-10-50-22
.. gh-issue: 73487
.. nonce: DUHbBq
.. section: Library
Speedup processing arguments (up to 1.5x) in the :mod:`decimal` module
methods, that now using :c:macro:`METH_FASTCALL` calling convention.  Patch
by Sergey B Kirpichev.
..
.. date: 2025-08-11-14-18-32
.. gh-issue: 137634
.. nonce: M7iBG6
.. section: Library
Calendar pages generated by the :class:`calendar.HTMLCalendar` class now
support dark mode and have been migrated to the HTML5 standard for improved
accessibility.
..
.. date: 2025-08-11-05-05-08
.. gh-issue: 137630
.. nonce: 9lmqyc
.. section: Library
The :mod:`!_interpreters` module now uses Argument Clinic to parse
arguments. Patch by Adam Turner.
..
.. date: 2025-08-09-08-53-32
.. gh-issue: 137583
.. nonce: s6OZud
.. section: Library
Fix a deadlock introduced in 3.13.6 when a call to :meth:`ssl.SSLSocket.recv
<socket.socket.recv>` was blocked in one thread, and then another method on
the object (such as :meth:`ssl.SSLSocket.send <socket.socket.send>`) was
subsequently called in another thread.
..
.. date: 2025-08-08-21-20-14
.. gh-issue: 92936
.. nonce: rOgG1S
.. section: Library
Update regex used by ``http.cookies.SimpleCookie`` to handle values
containing double quotes.
..
.. date: 2025-08-08-15-00-38
.. gh-issue: 137426
.. nonce: lW-Rk2
.. section: Library
Remove the code deprecation of ``importlib.abc.ResourceLoader``. It is
documented as deprecated, but left for backwards compatibility with other
classes in ``importlib.abc``.
..
.. date: 2025-08-07-17-18-57
.. gh-issue: 137490
.. nonce: s89ieZ
.. section: Library
Handle :data:`~errno.ECANCELED` in the same way as :data:`~errno.EINTR` in
:func:`signal.sigwaitinfo` on NetBSD.
..
.. date: 2025-08-07-15-07-44
.. gh-issue: 137512
.. nonce: j2or5h
.. section: Library
Add new constants in the :mod:`resource` module:
:data:`~resource.RLIMIT_NTHR`, :data:`~resource.RLIMIT_UMTXP`,
:data:`~resource.RLIMIT_PIPEBUF`, :data:`~resource.RLIMIT_THREADS`,
:data:`~resource.RLIM_SAVED_CUR`, and :data:`~resource.RLIM_SAVED_MAX`.
..
.. date: 2025-08-07-12-32-23
.. gh-issue: 137044
.. nonce: abNoIy
.. section: Library
:data:`resource.RLIM_INFINITY` is now always a positive integer. On all
supported platforms, it is larger than any limited resource value, which
simplifies comparison of the resource values. Previously, it could be
negative, such as -1 or -3, depending on platform.
..
.. date: 2025-08-06-23-16-42
.. gh-issue: 137477
.. nonce: bk6BDV
.. section: Library
Fix :func:`!inspect.getblock`, :func:`inspect.getsourcelines` and
:func:`inspect.getsource` for generator expressions.
..
.. date: 2025-08-06-16-54-22
.. gh-issue: 137481
.. nonce: eSTkK0
.. section: Library
Calendar uses the lengths of the locale's weekdays to decide if the width
requires abbreviation.
..
.. date: 2025-08-06-16-13-47
.. gh-issue: 137466
.. nonce: Whv0-A
.. section: Library
Remove undocumented :func:`!glob.glob0` and :func:`!glob.glob1` functions,
which have been deprecated since Python 3.13. Use :func:`glob.glob` and pass
a directory to its *root_dir* argument instead.
..
.. date: 2025-08-03-13-16-39
.. gh-issue: 137044
.. nonce: 0hPVL_
.. section: Library
Return large limit values as positive integers instead of negative integers
in :func:`resource.getrlimit`. Accept large values and reject negative
values (except :data:`~resource.RLIM_INFINITY`) for limits in
:func:`resource.setrlimit`.
..
.. date: 2025-08-03-00-36-57
.. gh-issue: 115766
.. nonce: nJCFkW
.. section: Library
Fix :attr:`!ipaddress.IPv4Interface.is_unspecified`.
..
.. date: 2025-08-01-23-52-49
.. gh-issue: 75989
.. nonce: 5aYXNJ
.. section: Library
:func:`tarfile.TarFile.extractall` and :func:`tarfile.TarFile.extract` now
overwrite symlinks when extracting hardlinks. (Contributed by Alexander
Enrique Urieles Nieto in :gh:`75989`.)
..
.. date: 2025-08-01-23-11-25
.. gh-issue: 137017
.. nonce: 0yGcNc
.. section: Library
Fix :obj:`threading.Thread.is_alive` to remain ``True`` until the underlying
OS thread is fully cleaned up. This avoids false negatives in edge cases
involving thread monitoring or premature :obj:`threading.Thread.is_alive`
calls.
..
.. date: 2025-08-01-15-07-59
.. gh-issue: 137273
.. nonce: 4V8Xmv
.. section: Library
Fix debug assertion failure in :func:`locale.setlocale` on Windows.
..
.. date: 2025-07-31-16-43-16
.. gh-issue: 137191
.. nonce: FIogE8
.. section: Library
Fix how type parameters are collected, when :class:`typing.Protocol` are
specified with explicit parameters. Now, :class:`typing.Generic` and
:class:`typing.Protocol` always dictate the parameter number and parameter
ordering of types. Previous behavior was a bug.
..
.. date: 2025-07-31-10-31-56
.. gh-issue: 137282
.. nonce: GOCwIC
.. section: Library
Fix tab completion and :func:`dir` on :mod:`concurrent.futures`.
..
.. date: 2025-07-30-18-07-33
.. gh-issue: 137257
.. nonce: XBtzf2
.. section: Library
Bump the version of pip bundled in ensurepip to version 25.2
..
.. date: 2025-07-30-17-42-36
.. gh-issue: 137239
.. nonce: qSpj32
.. section: Library
:mod:`heapq`: Update :data:`!heapq.__all__` with ``*_max`` functions.
..
.. date: 2025-07-30-11-12-22
.. gh-issue: 124503
.. nonce: d4hc7b
.. section: Library
:func:`ast.literal_eval` is 10-20% faster for small inputs.
..
.. date: 2025-07-29-21-18-31
.. gh-issue: 137226
.. nonce: B_4lpu
.. section: Library
Fix behavior of :meth:`annotationlib.ForwardRef.evaluate` when the
*type_params* parameter is passed and the name of a type param is also
present in an enclosing scope.
..
.. date: 2025-07-29-05-12-50
.. gh-issue: 137197
.. nonce: bMK3sO
.. section: Library
:class:`~ssl.SSLContext` objects can now set TLS 1.3 cipher suites via
:meth:`~ssl.SSLContext.set_ciphersuites`.
..
.. date: 2025-07-28-23-11-29
.. gh-issue: 81325
.. nonce: jMJFBe
.. section: Library
:class:`tarfile.TarFile` now accepts a :term:`path-like <path-like object>`
when working on a tar archive. (Contributed by Alexander Enrique Urieles
Nieto in :gh:`81325`.)
..
.. date: 2025-07-28-20-48-32
.. gh-issue: 137185
.. nonce: fgI7-B
.. section: Library
Fix a potential async-signal-safety issue in :mod:`faulthandler` when
printing C stack traces.
..
.. date: 2025-07-27-17-03-17
.. gh-issue: 133951
.. nonce: 7kwt78
.. section: Library
Remove lib64-lib symlink creation when creating new virtual environments in
:mod:`venv` module
..
.. date: 2025-07-25-09-21-56
.. gh-issue: 130522
.. nonce: Crwq68
.. section: Library
Fix unraisable :exc:`TypeError` raised during :term:`interpreter shutdown`
in the :mod:`threading` module.
..
.. date: 2025-07-24-00-38-07
.. gh-issue: 137059
.. nonce: fr64oW
.. section: Library
Fix handling of file URLs with a Windows drive letter in the URL authority
by :func:`urllib.request.url2pathname`. This fixes a regression in earlier
pre-releases of Python 3.14.
..
.. date: 2025-07-23-11-59-48
.. gh-issue: 136980
.. nonce: BIJzkB
.. section: Library
Remove unused C tracing code in bdb for event type ``c_call``, ``c_return``
and ``c_exception``
..
.. date: 2025-07-23-00-35-29
.. gh-issue: 130577
.. nonce: c7EITy
.. section: Library
:mod:`tarfile` now validates archives to ensure member offsets are
non-negative.  (Contributed by Alexander Enrique Urieles Nieto in
:gh:`130577`.)
..
.. date: 2025-07-21-22-35-50
.. gh-issue: 136170
.. nonce: QUlc78
.. section: Library
Removed the unreleased ``zipfile.ZipFile.data_offset`` property added in
3.14.0a7 as it wasn't fully clear which behavior it should have in some
situations so the result was not always what a user might expect.
..
.. date: 2025-07-21-20-00-42
.. gh-issue: 121237
.. nonce: DyxNqo
.. section: Library
Support ``%:z`` directive for :meth:`datetime.datetime.strptime`,
:meth:`datetime.time.strptime` and :func:`time.strptime`. Patch by Lucas
Esposito and Semyon Moroz.
..
.. date: 2025-07-21-16-13-20
.. gh-issue: 136929
.. nonce: obKZ2S
.. section: Library
Ensure that hash functions guaranteed to be always *available* exist as
attributes of :mod:`hashlib` even if they will not work at runtime due to
missing backend implementations. For instance, ``hashlib.md5`` will no
longer raise :exc:`AttributeError` if OpenSSL is not available and Python
has been built without MD5 support. Patch by Bénédikt Tran.
..
.. date: 2025-07-21-16-10-24
.. gh-issue: 124621
.. nonce: wyoWc1
.. section: Library
pyrepl now works in Emscripten.
..
.. date: 2025-07-21-15-40-00
.. gh-issue: 136914
.. nonce: -GNG-d
.. section: Library
Fix retrieval of :attr:`doctest.DocTest.lineno` for objects decorated with
:func:`functools.cache` or :class:`functools.cached_property`.
..
.. date: 2025-07-21-11-56-47
.. gh-issue: 136912
.. nonce: zWosAL
.. section: Library
:func:`hmac.digest` now properly handles large keys and messages by falling
back to the pure Python implementation when necessary. Patch by Bénédikt
Tran.
..
.. date: 2025-07-21-01-16-32
.. gh-issue: 83424
.. nonce: Y3tEV4
.. section: Library
Allows creating a :class:`ctypes.CDLL` without name when passing a handle as
an argument.
..
.. date: 2025-07-20-16-56-55
.. gh-issue: 135228
.. nonce: n_XIao
.. section: Library
When :mod:`dataclasses` replaces a class with a slotted dataclass, the
original class can now be garbage collected again. Earlier changes in Python
3.14 caused this class to always remain in existence together with the
replacement class synthesized by :mod:`dataclasses`.
..
.. date: 2025-07-20-16-02-00
.. gh-issue: 136874
.. nonce: cLC3o1
.. section: Library
Discard URL query and fragment in :func:`urllib.request.url2pathname`.
..
.. date: 2025-07-20-10-21-49
.. gh-issue: 136787
.. nonce: _0Rbp_
.. section: Library
:mod:`hashlib`: improve exception messages when a hash algorithm is not
recognized, blocked by the current security policy or incompatible with the
desired operation (for instance, using HMAC with SHAKE). Patch by Bénédikt
Tran.
..
.. date: 2025-07-19-16-20-54
.. gh-issue: 130645
.. nonce: O-dYcN
.. section: Library
Enable color help by default in :mod:`argparse`.
..
.. date: 2025-07-19-15-40-47
.. gh-issue: 131724
.. nonce: LS59nA
.. section: Library
In :mod:`http.client`, a new *max_response_headers* keyword-only parameter
has been added to :class:`~http.client.HTTPConnection` and
:class:`~http.client.HTTPSConnection` constructors. This parameter sets the
maximum number of allowed response headers, helping to prevent
denial-of-service attacks.
..
.. date: 2025-07-19-11-53-19
.. gh-issue: 135427
.. nonce: iJM_X2
.. section: Library
With :option:`-Werror <-W>`, the DeprecationWarning emitted by
:py:func:`os.fork` and :py:func:`os.forkpty` in mutli-threaded processes is
now raised as an exception. Previously it was silently ignored. Patch by
Rani Pinchuk.
..
.. date: 2025-07-17-16-12-23
.. gh-issue: 136234
.. nonce: VmTxtj
.. section: Library
Fix :meth:`asyncio.WriteTransport.writelines` to be robust to connection
failure, by using the same behavior as
:meth:`~asyncio.WriteTransport.write`.
..
.. date: 2025-07-16-09-45-58
.. gh-issue: 53144
.. nonce: mrKwMW
.. section: Library
:mod:`!encodings.aliases`: Add ``latin_N`` aliases
..
.. date: 2025-07-15-16-37-34
.. gh-issue: 136669
.. nonce: Yexwah
.. section: Library
:mod:`!_asyncio` is now statically linked for improved performance.
..
.. date: 2025-07-13-13-31-22
.. gh-issue: 136134
.. nonce: mh6VjS
.. section: Library
:meth:`!SMTP.auth_cram_md5` now raises an :exc:`~smtplib.SMTPException`
instead of a :exc:`ValueError` if Python has been built without MD5 support.
In particular, :class:`~smtplib.SMTP` clients will not attempt to use this
method even if the remote server is assumed to support it. Patch by Bénédikt
Tran.
..
.. date: 2025-07-13-11-20-05
.. gh-issue: 136134
.. nonce: xhh0Kq
.. section: Library
:meth:`IMAP4.login_cram_md5 <imaplib.IMAP4.login_cram_md5>` now raises an
:exc:`IMAP4.error <imaplib.IMAP4.error>` if CRAM-MD5 authentication is not
supported. Patch by Bénédikt Tran.
..
.. date: 2025-07-12-18-05-37
.. gh-issue: 136591
.. nonce: ujXmSN
.. section: Library
:mod:`!_hashlib`: avoid using deprecated functions
:manpage:`ERR_func_error_string` and :manpage:`EVP_MD_CTX_md` when using
OpenSSL 3.0 and later. Patch by Bénédikt Tran.
..
.. date: 2025-07-12-14-15-47
.. gh-issue: 136571
.. nonce: muHmBv
.. section: Library
:meth:`datetime.date.fromisocalendar` can now raise OverflowError for out of
range arguments.
..
.. date: 2025-07-11-23-04-39
.. gh-issue: 136549
.. nonce: oAi8u4
.. section: Library
Fix signature of :func:`threading.excepthook`.
..
.. date: 2025-07-11-10-23-44
.. gh-issue: 136492
.. nonce: BVi5h0
.. section: Library
Expose :pep:`667`'s :data:`~types.FrameLocalsProxyType` in the :mod:`types`
module.
..
.. date: 2025-07-11-08-15-17
.. gh-issue: 83336
.. nonce: ptpmq7
.. section: Library
``utf8_sig`` is now aliased to :mod:`encodings.utf_8_sig`
..
.. date: 2025-07-11-03-39-15
.. gh-issue: 136523
.. nonce: s7caKL
.. section: Library
Fix :class:`wave.Wave_write` emitting an unraisable when open raises.
..
.. date: 2025-07-10-21-02-43
.. gh-issue: 136507
.. nonce: pnEuGS
.. section: Library
Fix mimetypes CLI to handle multiple file parameters.
..
.. date: 2025-07-10-10-18-19
.. gh-issue: 52876
.. nonce: 9Vjrd8
.. section: Library
Add missing ``keepends`` (default ``True``) parameter to
:meth:`!codecs.StreamReaderWriter.readline` and
:meth:`!codecs.StreamReaderWriter.readlines`.
..
.. date: 2025-07-10-00-47-37
.. gh-issue: 136470
.. nonce: KlUEUG
.. section: Library
Correct :class:`concurrent.futures.InterpreterPoolExecutor`'s default thread
name.
..
.. date: 2025-07-09-20-29-30
.. gh-issue: 136476
.. nonce: HyLLzh
.. section: Library
Fix a bug that was causing the ``get_async_stack_trace`` function to miss
some frames in the stack trace.
..
.. date: 2025-07-08-20-58-01
.. gh-issue: 136434
.. nonce: uuJsjS
.. section: Library
Fix docs generation of ``UnboundItem`` in :mod:`concurrent.interpreters`
when running with :option:`-OO`.
..
.. date: 2025-07-07-22-12-32
.. gh-issue: 136380
.. nonce: 1b_nXl
.. section: Library
Raises :exc:`AttributeError` when accessing
:class:`concurrent.futures.InterpreterPoolExecutor` and subinterpreters are
not available.
..
.. date: 2025-07-07-16-46-55
.. gh-issue: 72327
.. nonce: wLvRuj
.. section: Library
Suggest using the system command prompt when ``pip install`` is typed into
the REPL. Patch by Tom Viner, Richard Si, and Brian Schubert.
..
.. date: 2025-07-06-18-38-10
.. gh-issue: 135953
.. nonce: Z29DCz
.. section: Library
Implement a new high-frequency runtime profiler that leverages the existing
remote debugging functionality to collect detailed execution statistics from
running Python processes. This tool is exposed in the ``profile.sample``
module and enables non-intrusive observation of production applications by
attaching to already-running processes without requiring any code
modifications, restarts, or special startup flags. The observer can perform
extremely high-frequency sampling of stack traces and interpreter state,
providing detailed runtime execution analysis of live applications.
..
.. date: 2025-07-06-10-18-48
.. gh-issue: 136021
.. nonce: f-FJYT
.. section: Library
Make ``type_params`` parameter required in :func:`!typing._eval_type` after
a deprecation period for not providing this parameter. Also remove the
:exc:`DeprecationWarning` for the old behavior.
..
.. date: 2025-07-05-09-45-04
.. gh-issue: 136286
.. nonce: N67Amr
.. section: Library
Fix pickling failures for protocols 0 and 1 for many objects related to
subinterpreters.
..
.. date: 2025-07-05-06-59-46
.. gh-issue: 136047
.. nonce: qWvycf
.. section: Library
Fix issues with :mod:`typing` when the C implementation of :mod:`abc` is not
available.
..
.. date: 2025-07-05-06-56-16
.. gh-issue: 136316
.. nonce: 3zj_Do
.. section: Library
Improve support for evaluating nested forward references in
:func:`typing.evaluate_forward_ref`.
..
.. date: 2025-07-04-23-45-00
.. gh-issue: 136306
.. nonce: O1YLIU
.. section: Library
:mod:`ssl` can now get and set groups used for key agreement.
..
.. date: 2025-07-04-12-53-02
.. gh-issue: 136156
.. nonce: OYlXoz
.. section: Library
:func:`tempfile.TemporaryFile` no longer uses :data:`os.O_EXCL` with
:data:`os.O_TMPFILE`, so it's possible to use ``linkat()`` on the file
descriptor. Patch by Victor Stinner.
..
.. date: 2025-07-02-18-41-45
.. gh-issue: 133982
.. nonce: 7qqAn6
.. section: Library
Update Python implementation of :class:`io.BytesIO` to be thread safe.
..
.. date: 2025-07-02-10-48-21
.. gh-issue: 136193
.. nonce: xfvras
.. section: Library
Improve :exc:`TypeError` error message, when richcomparing two
:class:`types.SimpleNamespace` objects.
..
.. date: 2025-07-01-14-44-03
.. gh-issue: 136097
.. nonce: bI1n14
.. section: Library
Fix potential infinite recursion and KeyError in ``sysconfig
--generate-posix-vars``.
..
.. date: 2025-06-30-11-12-24
.. gh-issue: 85702
.. nonce: 0Lrbwu
.. section: Library
If ``zoneinfo._common.load_tzdata`` is given a package without a resource a
:exc:`zoneinfo.ZoneInfoNotFoundError` is raised rather than a
:exc:`PermissionError`. Patch by Victor Stinner.
..
.. date: 2025-06-29-15-22-13
.. gh-issue: 90733
.. nonce: NiquaA
.. section: Library
Improve error messages when reporting invalid parameters in
:func:`hashlib.scrypt`. Patch by Bénédikt Tran.
..
.. date: 2025-06-28-11-32-57
.. gh-issue: 134759
.. nonce: AjjKcG
.. section: Library
Fix :exc:`UnboundLocalError` in :func:`email.message.Message.get_payload`
when the payload to decode is a :class:`bytes` object. Patch by Kliment
Lamonov.
..
.. date: 2025-06-27-13-34-28
.. gh-issue: 136028
.. nonce: RY727g
.. section: Library
Fix parsing month names containing "İ" (U+0130, LATIN CAPITAL LETTER I WITH
DOT ABOVE) in :func:`time.strptime`. This affects locales az_AZ, ber_DZ,
ber_MA and crh_UA.
..
.. date: 2025-06-27-09-26-04
.. gh-issue: 87135
.. nonce: 33z0UW
.. section: Library
Acquiring a :class:`threading.Lock` or :class:`threading.RLock` at
interpreter shutdown will raise :exc:`PythonFinalizationError` if Python can
determine that it would otherwise deadlock.
..
.. date: 2025-06-26-17-28-49
.. gh-issue: 135995
.. nonce: pPrDCt
.. section: Library
In the palmos encoding, make byte ``0x9b`` decode to ``›`` (U+203A - SINGLE
RIGHT-POINTING ANGLE QUOTATION MARK).
..
.. date: 2025-06-26-17-19-36
.. gh-issue: 105456
.. nonce: eR9oHB
.. section: Library
Removed :mod:`!sre_compile`, :mod:`!sre_constants` and :mod:`!sre_parse`
modules.
..
.. date: 2025-06-26-11-52-40
.. gh-issue: 53203
.. nonce: TMigBr
.. section: Library
Fix :func:`time.strptime` for ``%c`` and ``%x`` formats on locales byn_ER,
wal_ET and lzh_TW, and for ``%X`` format on locales ar_SA, bg_BG and lzh_TW.
..
.. date: 2025-06-24-14-43-24
.. gh-issue: 135878
.. nonce: Db4roX
.. section: Library
Fixes a crash of :class:`types.SimpleNamespace` on :term:`free threading`
builds, when several threads were calling its :meth:`~object.__repr__`
method at the same time.
..
.. date: 2025-06-24-13-30-47
.. gh-issue: 135853
.. nonce: 7ejTvK
.. section: Library
Add :func:`math.fmax` and :func:`math.fmin` to get the larger and smaller of
two floating-point values. Patch by Bénédikt Tran.
..
.. date: 2025-06-24-10-52-35
.. gh-issue: 135836
.. nonce: s37351
.. section: Library
Fix :exc:`IndexError` in :meth:`asyncio.loop.create_connection` that could
occur when non-\ :exc:`OSError` exception is raised during connection and
socket's ``close()`` raises :exc:`!OSError`.
..
.. date: 2025-06-24-10-23-37
.. gh-issue: 135853
.. nonce: 6xDNOG
.. section: Library
:mod:`math`: expose C99 :func:`~math.signbit` function to determine whether
the sign bit of a floating-point value is set. Patch by Bénédikt Tran.
..
.. date: 2025-06-23-13-02-08
.. gh-issue: 134531
.. nonce: yUmj07
.. section: Library
:mod:`hmac`: use the :manpage:`EVP_MAC(3ssl)` interface for HMAC when Python
is built with OpenSSL 3.0 and later instead of the deprecated
:manpage:`HMAC_CTX(3ssl) <hmac(3)>` interface. Patch by Bénédikt Tran.
..
.. date: 2025-06-23-11-04-25
.. gh-issue: 135836
.. nonce: -C-c4v
.. section: Library
Fix :exc:`IndexError` in :meth:`asyncio.loop.create_connection` that could
occur when the Happy Eyeballs algorithm resulted in an empty exceptions list
during connection attempts.
..
.. date: 2025-06-23-10-19-11
.. gh-issue: 135855
.. nonce: -J0AGF
.. section: Library
Raise :exc:`TypeError` instead of :exc:`SystemError` when
:func:`!_interpreters.set___main___attrs` is passed a non-dict object. Patch
by Brian Schubert.
..
.. date: 2025-06-22-22-03-06
.. gh-issue: 135823
.. nonce: iDBg97
.. section: Library
:mod:`netrc`: improve the error message when the security check for the
ownership of the default configuration file ``~/.netrc`` fails. Patch by
Bénédikt Tran.
..
.. date: 2025-06-22-16-23-44
.. gh-issue: 135815
.. nonce: 0DandH
.. section: Library
:mod:`netrc`: skip security checks if :func:`os.getuid` is missing. Patch by
Bénédikt Tran.
..
.. date: 2025-06-22-02-16-17
.. gh-issue: 135640
.. nonce: FXyFL6
.. section: Library
Address bug where it was possible to call
:func:`xml.etree.ElementTree.ElementTree.write` on an ElementTree object
with an invalid root element. This behavior blanked the file passed to
``write`` if it already existed.
..
.. date: 2025-06-20-17-06-59
.. gh-issue: 90117
.. nonce: GYWVrn
.. section: Library
Speed up :mod:`pprint` for :class:`list` and :class:`tuple`.
..
.. date: 2025-06-20-16-28-47
.. gh-issue: 135759
.. nonce: jne0Zi
.. section: Library
:mod:`hashlib`: reject negative digest lengths in OpenSSL-based SHAKE
objects by raising a :exc:`ValueError`. Previously, negative lengths were
implicitly rejected by raising a :exc:`MemoryError` or a :exc:`SystemError`.
Patch by Bénédikt Tran.
..
.. date: 2025-06-18-19-25-32
.. gh-issue: 123471
.. nonce: lx1Xbt
.. section: Library
Make concurrent iterations over :class:`itertools.chain` safe under
:term:`free threading`.
..
.. date: 2025-06-18-13-58-13
.. gh-issue: 135645
.. nonce: 109nff
.. section: Library
Added ``supports_isolated_interpreters`` field to
:data:`sys.implementation`.
..
.. date: 2025-06-18-11-43-17
.. gh-issue: 135646
.. nonce: r7ekEn
.. section: Library
Raise consistent :exc:`NameError` exceptions in
:func:`annotationlib.ForwardRef.evaluate`
..
.. date: 2025-06-17-23-13-56
.. gh-issue: 135557
.. nonce: Bfcy4v
.. section: Library
Fix races on :mod:`heapq` updates and :class:`list` reads on the :term:`free
threaded <free threading>` build.
..
.. date: 2025-06-17-22-44-19
.. gh-issue: 119180
.. nonce: Ogv8Nj
.. section: Library
Only fetch globals and locals if necessary in
:func:`annotationlib.get_annotations`
..
.. date: 2025-06-16-15-03-03
.. gh-issue: 135561
.. nonce: mJCN8D
.. section: Library
Fix a crash on DEBUG builds when an HACL* HMAC routine fails. Patch by
Bénédikt Tran.
..
.. date: 2025-06-16-15-00-13
.. gh-issue: 135386
.. nonce: lNrxLc
.. section: Library
Fix opening a :mod:`dbm.sqlite3` database for reading from read-only file or
directory.
..
.. date: 2025-06-16-12-37-02
.. gh-issue: 135444
.. nonce: An2eeA
.. section: Library
Fix :meth:`asyncio.DatagramTransport.sendto` to account for datagram header
size when data cannot be sent.
..
.. date: 2025-06-15-03-03-22
.. gh-issue: 65697
.. nonce: COdwZd
.. section: Library
:class:`configparser`'s error message when attempting to write an invalid
key is now more helpful.
..
.. date: 2025-06-14-14-19-13
.. gh-issue: 135497
.. nonce: 1pzwdA
.. section: Library
Fix :func:`os.getlogin` failing for longer usernames on BSD-based platforms.
..
.. date: 2025-06-14-12-06-55
.. gh-issue: 135487
.. nonce: KdVFff
.. section: Library
Fix :meth:`!reprlib.Repr.repr_int` when given integers with more than
:func:`sys.get_int_max_str_digits` digits. Patch by Bénédikt Tran.
..
.. date: 2025-06-12-18-15-31
.. gh-issue: 135429
.. nonce: mch75_
.. section: Library
Fix the argument mismatch in ``_lsprof`` for ``PY_THROW`` event.
..
.. date: 2025-06-12-10-45-02
.. gh-issue: 135368
.. nonce: OjWVHL
.. section: Library
Fix :class:`unittest.mock.Mock` generation on :func:`dataclasses.dataclass`
objects. Now all special attributes are set as it was before :gh:`124429`.
..
.. date: 2025-06-11-15-08-02
.. gh-issue: 135336
.. nonce: 6Gq6MI
.. section: Library
:mod:`json` now encodes strings up to 2.2x faster if they consist solely of
characters that don’t require escaping.
..
.. date: 2025-06-10-21-42-04
.. gh-issue: 135335
.. nonce: WnUqb_
.. section: Library
:mod:`multiprocessing`: Flush ``stdout`` and ``stderr`` after preloading
modules in the ``forkserver``.
..
.. date: 2025-06-10-21-00-48
.. gh-issue: 126631
.. nonce: eITVJd
.. section: Library
Fix :mod:`multiprocessing` ``forkserver`` bug which prevented ``__main__``
from being preloaded.
..
.. date: 2025-06-10-16-11-00
.. gh-issue: 133967
.. nonce: P0c24q
.. section: Library
Do not normalize :mod:`locale` name 'C.UTF-8' to 'en_US.UTF-8'.
..
.. date: 2025-06-10-10-22-18
.. gh-issue: 130870
.. nonce: JipqbO
.. section: Library
Preserve :class:`types.GenericAlias` subclasses in
:func:`typing.get_type_hints`
..
.. date: 2025-06-10-00-42-30
.. gh-issue: 135321
.. nonce: UHh9jT
.. section: Library
Raise a correct exception for values greater than 0x7fffffff for the
``BINSTRING`` opcode in the C implementation of :mod:`pickle`.
..
.. date: 2025-06-09-10-16-55
.. gh-issue: 121914
.. nonce: G6Avkq
.. section: Library
Changed the names of the symbol tables for lambda expressions and generator
expressions to "<lambda>" and "<genexpr>" respectively to avoid conflicts
with user-defined names.
..
.. date: 2025-06-08-14-50-34
.. gh-issue: 135276
.. nonce: ZLUhV1
.. section: Library
Synchronized zipfile.Path with zipp 3.23, including improved performance of
:meth:`zipfile.Path.open` for non-reading modes, rely on
:func:`functools.cached_property` to cache values on the instance. Rely on
``save_method_args`` to save the initialization method arguments. Fixed
``.name``, ``.stem`` and other basename-based properties on Windows when
working with a zipfile on disk.
..
.. date: 2025-06-08-11-11-07
.. gh-issue: 135234
.. nonce: wJCdh0
.. section: Library
:mod:`hashlib`: improve exception messages when an OpenSSL function failed.
When memory allocation fails on OpenSSL's side, a :exc:`MemoryError` is
raised instead of a :exc:`ValueError`. Patch by Bénédikt Tran.
..
.. date: 2025-06-08-10-22-22
.. gh-issue: 135244
.. nonce: Y2SOTJ
.. section: Library
:mod:`uuid`: when the MAC address cannot be determined, the 48-bit node ID
is now generated with a cryptographically-secure pseudo-random number
generator (CSPRNG) as per :rfc:`RFC 9562, §6.10.3 <9562#section-6.10-3>`.
This affects :func:`~uuid.uuid1` and :func:`~uuid.uuid6`.
..
.. date: 2025-06-08-01-10-34
.. gh-issue: 135241
.. nonce: 5j18IW
.. section: Library
The :code:`INT` opcode of the C accelerator :mod:`!_pickle` module was
updated to look only for "00" and "01" to push booleans onto the stack,
aligning with the Python :mod:`pickle` module.
..
.. date: 2025-06-06-17-34-18
.. gh-issue: 133934
.. nonce: yT1r68
.. section: Library
Improve :mod:`sqlite3` CLI's ``.help`` message.
..
.. date: 2025-06-03-12-59-17
.. gh-issue: 135069
.. nonce: xop30V
.. section: Library
Fix the "Invalid error handling" exception in
:class:`!encodings.idna.IncrementalDecoder` to correctly replace the
'errors' parameter.
..
.. date: 2025-06-02-14-36-28
.. gh-issue: 130662
.. nonce: Gpr2GB
.. section: Library
+Accept leading zeros in precision and width fields for
+:class:`~decimal.Decimal` formatting, for example ``format(Decimal(1.25),
'.016f')``.
..
.. date: 2025-06-02-14-28-30
.. gh-issue: 130662
.. nonce: EIgIR8
.. section: Library
Accept leading zeros in precision and width fields for
:class:`~fractions.Fraction` formatting, for example ``format(Fraction(1,
3), '.016f')``.
..
.. date: 2025-06-01-14-18-48
.. gh-issue: 135004
.. nonce: cq3-fp
.. section: Library
Rewrite and cleanup the internal :mod:`!_blake2` module. Some exception
messages were changed but their types were left untouched. Patch by Bénédikt
Tran.
..
.. date: 2025-06-01-11-14-00
.. gh-issue: 134953
.. nonce: ashdfs
.. section: Library
Expand ``_colorize`` theme with ``keyword_constant`` and implement in
:term:`repl`.
..
.. date: 2025-05-31-15-49-46
.. gh-issue: 134978
.. nonce: mXXuvW
.. section: Library
:mod:`hashlib`: Supporting the ``string`` keyword parameter in hash function
constructors such as :func:`~hashlib.new` or the direct hash-named
constructors such as :func:`~hashlib.md5` and :func:`~hashlib.sha256` is now
deprecated and slated for removal in Python 3.19. Prefer passing the initial
data as a positional argument for maximum backwards compatibility. Patch by
Bénédikt Tran.
..
.. date: 2025-05-31-12-08-12
.. gh-issue: 134970
.. nonce: lgSaxq
.. section: Library
Fix the "unknown action" exception in
:meth:`argparse.ArgumentParser.add_argument_group` to correctly replace the
action class.
..
.. date: 2025-05-30-18-13-48
.. gh-issue: 134718
.. nonce: 5FEspx
.. section: Library
By default, omit optional ``Load()`` values in :func:`ast.dump`.
..
.. date: 2025-05-30-13-07-29
.. gh-issue: 134718
.. nonce: 9Qvhxn
.. section: Library
:func:`ast.dump` now only omits ``None`` and ``[]`` values if they are
default values.
..
.. date: 2025-05-30-09-46-21
.. gh-issue: 134939
.. nonce: Pu3nnm
.. section: Library
Add the :mod:`concurrent.interpreters` module.  See :pep:`734`.
..
.. date: 2025-05-29-17-39-13
.. gh-issue: 108885
.. nonce: MegCRA
.. section: Library
Run each example as a subtest in unit tests synthesized by
:func:`doctest.DocFileSuite` and :func:`doctest.DocTestSuite`. Add the
:meth:`doctest.DocTestRunner.report_skip` method.
..
.. date: 2025-05-29-06-53-40
.. gh-issue: 134885
.. nonce: -_L22o
.. section: Library
Fix possible crash in the :mod:`compression.zstd` module related to setting
parameter types. Patch by Jelle Zijlstra.
..
.. date: 2025-05-28-20-49-29
.. gh-issue: 134857
.. nonce: dVYXVO
.. section: Library
Improve error report for :mod:`doctest`\ s run with :mod:`unittest`. Remove
:mod:`!doctest` module frames from tracebacks and redundant newline
character from a failure message.
..
.. date: 2025-05-28-15-53-27
.. gh-issue: 128840
.. nonce: Nur2pB
.. section: Library
Fix parsing long IPv6 addresses with embedded IPv4 address.
..
.. date: 2025-05-27-11-24-38
.. gh-issue: 133579
.. nonce: WGPUC1
.. section: Library
:mod:`curses`: Consistently report failures of curses C API calls in
module-level methods by raising a :exc:`curses.error`. This affects
:func:`~curses.assume_default_colors`, :func:`~curses.baudrate`,
:func:`~curses.cbreak`, :func:`~curses.echo`, :func:`~curses.longname`,
:func:`~curses.initscr`, :func:`~curses.nl`, :func:`~curses.raw`,
:func:`~curses.termattrs`, :func:`~curses.termname` and
:func:`~curses.unctrl`. Patch by Bénédikt Tran.
..
.. date: 2025-05-27-11-18-13
.. gh-issue: 133579
.. nonce: ohtgdC
.. section: Library
:meth:`curses.window.refresh` and :meth:`curses.window.noutrefresh` now
raise a :exc:`TypeError` instead of :exc:`curses.error` when called with an
incorrect number of arguments for :ref:`pads <windows-and-pads>`. Patch by
Bénédikt Tran.
..
.. date: 2025-05-27-11-13-51
.. gh-issue: 133579
.. nonce: KY9M6S
.. section: Library
:ref:`curses.window <curses-window-objects>`: Consistently report failures
of curses C API calls in Window methods by raising a :exc:`curses.error`.
This affects :meth:`~curses.window.addch`, :meth:`~curses.window.addnstr`,
:meth:`~curses.window.addstr`, :meth:`~curses.window.border`,
:meth:`~curses.window.box`, :meth:`~curses.window.chgat`,
:meth:`~curses.window.getbkgd`, :meth:`~curses.window.inch`,
:meth:`~curses.window.insstr` and :meth:`~curses.window.insnstr`. Patch by
Bénédikt Tran.
..
.. date: 2025-05-26-22-18-32
.. gh-issue: 134771
.. nonce: RKXpLT
.. section: Library
The ``time_clockid_converter()`` function now selects correct type for
``clockid_t`` on Cygwin which fixes a build error.
..
.. date: 2025-05-26-17-06-40
.. gh-issue: 134637
.. nonce: 9-3zRL
.. section: Library
Fix performance regression in calling a :mod:`ctypes` function pointer in
:term:`free threading`.
..
.. date: 2025-05-26-14-04-39
.. gh-issue: 134696
.. nonce: P04xUa
.. section: Library
Built-in HACL* and OpenSSL implementations of hash function constructors now
correctly accept the same *documented* named arguments. For instance,
:func:`~hashlib.md5` could be previously invoked as ``md5(data=data)`` or
``md5(string=string)`` depending on the underlying implementation but these
calls were not compatible. Patch by Bénédikt Tran.
..
.. date: 2025-05-26-12-31-08
.. gh-issue: 132710
.. nonce: ApU3TZ
.. section: Library
If possible, ensure that :func:`uuid.getnode` returns the same result even
across different processes. Previously, the result was constant only within
the same process. Patch by Bénédikt Tran.
..
.. date: 2025-05-26-11-01-54
.. gh-issue: 134531
.. nonce: my1Fzt
.. section: Library
:mod:`!_hashlib`: Rename internal C functions for :class:`!_hashlib.HASH`
and :class:`!_hashlib.HASHXOF` objects. Patch by Bénédikt Tran.
..
.. date: 2025-05-26-10-52-27
.. gh-issue: 134698
.. nonce: aJ1mZ1
.. section: Library
Fix a crash when calling methods of :class:`ssl.SSLContext` or
:class:`ssl.SSLSocket` across multiple threads.
..
.. date: 2025-05-25-23-23-05
.. gh-issue: 134151
.. nonce: 13Wwsb
.. section: Library
:mod:`email`: Fix :exc:`TypeError` in :func:`email.utils.decode_params` when
sorting :rfc:`2231` continuations that contain an unnumbered section.
..
.. date: 2025-05-25-13-46-37
.. gh-issue: 134635
.. nonce: ZlPrlX
.. section: Library
:mod:`zlib`: Allow to combine Adler-32 and CRC-32 checksums via
:func:`~zlib.adler32_combine` and :func:`~zlib.crc32_combine`. Patch by
Callum Attryde and Bénédikt Tran.
..
.. date: 2025-05-25-11-02-05
.. gh-issue: 134657
.. nonce: 3YFhR9
.. section: Library
:mod:`asyncio`: Remove some private names from ``asyncio.__all__``.
..
.. date: 2025-05-24-13-10-35
.. gh-issue: 134210
.. nonce: 0IuMY2
.. section: Library
:func:`curses.window.getch` now correctly handles signals. Patch by Bénédikt
Tran.
..
.. date: 2025-05-24-03-10-36
.. gh-issue: 80334
.. nonce: z21cMa
.. section: Library
:func:`multiprocessing.freeze_support` now checks for work on any "spawn"
start method platform rather than only on Windows.
..
.. date: 2025-05-23-23-43-39
.. gh-issue: 134582
.. nonce: 9POq3l
.. section: Library
Fix tokenize.untokenize() round-trip errors related to t-strings braces
escaping
..
.. date: 2025-05-23-20-01-52
.. gh-issue: 134580
.. nonce: xnaJ70
.. section: Library
Improved the styling of HTML diff pages generated by the
:class:`difflib.HtmlDiff` class, and migrated the output to the HTML5
standard.
..
.. date: 2025-05-23-10-15-36
.. gh-issue: 134565
.. nonce: zmb66C
.. section: Library
:func:`unittest.doModuleCleanups` no longer swallows all but first exception
raised in the cleanup code, but raises a :exc:`ExceptionGroup` if multiple
errors occurred.
..
.. date: 2025-05-22-18-14-13
.. gh-issue: 134546
.. nonce: fjLVzK
.. section: Library
Ensure :mod:`pdb` remote debugging script is readable by remote Python
process.
..
.. date: 2025-05-22-14-12-53
.. gh-issue: 134451
.. nonce: M1rD-j
.. section: Library
Converted ``asyncio.tools.CycleFoundException`` from dataclass to a regular
exception type.
..
.. date: 2025-05-22-13-10-32
.. gh-issue: 114177
.. nonce: 3TYUJ3
.. section: Library
Fix :mod:`asyncio` to not close subprocess pipes which would otherwise error
out when the event loop is already closed.
..
.. date: 2025-05-20-21-45-58
.. gh-issue: 90871
.. nonce: Gkvtp6
.. section: Library
Fixed an off by one error concerning the backlog parameter in
:meth:`~asyncio.loop.create_unix_server`. Contributed by Christian Harries.
..
.. date: 2025-05-20-19-16-30
.. gh-issue: 134323
.. nonce: ZQZGvw
.. section: Library
Fix the :meth:`threading.RLock.locked` method.
..
.. date: 2025-05-20-15-13-43
.. gh-issue: 86802
.. nonce: trF7TM
.. section: Library
Fixed asyncio memory leak in cancelled shield tasks. For shielded tasks
where the shield was cancelled, log potential exceptions through the
exception handler. Contributed by Christian Harries.
..
.. date: 2025-05-20-11-51-17
.. gh-issue: 71189
.. nonce: 0LpTB1
.. section: Library
Add support of the all-but-last mode in :func:`os.path.realpath`.
..
.. date: 2025-05-20-11-35-08
.. gh-issue: 72902
.. nonce: jzEI-E
.. section: Library
Improve speed (x1.1-1.8) of the :class:`~fractions.Fraction` constructor for
typical inputs (:class:`float`'s, :class:`~decimal.Decimal`'s or strings).
..
.. date: 2025-05-19-20-59-06
.. gh-issue: 134209
.. nonce: anhTcF
.. section: Library
:mod:`curses`: The :meth:`curses.window.instr` and
:meth:`curses.window.getstr` methods now allocate their internal buffer on
the heap instead of the stack; in addition, the max buffer size is increased
from 1023 to 2047.
..
.. date: 2025-05-19-18-12-42
.. gh-issue: 88994
.. nonce: 7avvVu
.. section: Library
Change :func:`datetime.datetime.now` to half-even rounding for consistency
with :func:`datetime.datetime.fromtimestamp`.  Patch by John Keith Hohm.
..
.. date: 2025-05-19-17-27-21
.. gh-issue: 80184
.. nonce: LOkbaw
.. section: Library
The default queue size is now ``socket.SOMAXCONN`` for
:class:`socketserver.TCPServer`.
..
.. date: 2025-05-19-15-30-00
.. gh-issue: 132983
.. nonce: asdsfs
.. section: Library
Add :mod:`!compression.zstd` version information to ``test.pythoninfo``.
..
.. date: 2025-05-19-15-05-24
.. gh-issue: 134235
.. nonce: pz9PwV
.. section: Library
Updated tab completion on REPL to include builtin modules. Contributed by
Tom Wang, Hunter Young
..
.. date: 2025-05-19-10-32-11
.. gh-issue: 134152
.. nonce: INJC2j
.. section: Library
Fixed :exc:`UnboundLocalError` that could occur during :mod:`email` header
parsing if an expected trailing delimiter is missing in some contexts.
..
.. date: 2025-05-18-23-46-21
.. gh-issue: 134152
.. nonce: 30HwbX
.. section: Library
:mod:`email`: Fix parsing of email message ID with invalid domain.
..
.. date: 2025-05-18-13-23-29
.. gh-issue: 134168
.. nonce: hgx3Xg
.. section: Library
:mod:`http.server`: Fix IPv6 address binding and :option:`--directory
<http.server --directory>` handling when using HTTPS.
..
.. date: 2025-05-18-12-48-39
.. gh-issue: 62184
.. nonce: y11l10
.. section: Library
Remove import of C implementation of :class:`io.FileIO` from Python
implementation which has its own implementation
..
.. date: 2025-05-18-12-23-07
.. gh-issue: 134087
.. nonce: HilZWl
.. section: Library
Remove support for arbitrary positional or keyword arguments in the C
implementation of :class:`threading.RLock` objects. This was deprecated
since Python 3.14. Patch by Bénédikt Tran.
..
.. date: 2025-05-18-07-25-15
.. gh-issue: 134173
.. nonce: 53oOoF
.. section: Library
Speed up :mod:`asyncio` performance of transferring state from thread pool
:class:`concurrent.futures.Future` by up to 4.4x. Patch by J. Nick Koston.
..
.. date: 2025-05-17-20-23-57
.. gh-issue: 133982
.. nonce: smS7au
.. section: Library
Emit :exc:`RuntimeWarning` in the Python implementation of :mod:`io` when
the :term:`file-like object <file object>` is not closed explicitly in the
presence of multiple I/O layers.
..
.. date: 2025-05-17-18-08-35
.. gh-issue: 133890
.. nonce: onn9_X
.. section: Library
The :mod:`tarfile` module now handles :exc:`UnicodeEncodeError` in the same
way as :exc:`OSError` when cannot extract a member.
..
.. date: 2025-05-17-13-46-20
.. gh-issue: 134097
.. nonce: fgkjE1
.. section: Library
Fix interaction of the new :term:`REPL` and :option:`-X showrefcount <-X>`
command line option.
..
.. date: 2025-05-17-12-40-12
.. gh-issue: 133889
.. nonce: Eh-zO4
.. section: Library
The generated directory listing page in
:class:`http.server.SimpleHTTPRequestHandler` now only shows the decoded
path component of the requested URL, and not the query and fragment.
..
.. date: 2025-05-16-20-10-25
.. gh-issue: 134098
.. nonce: YyTkKr
.. section: Library
Fix handling paths that end with a percent-encoded slash (``%2f`` or
``%2F``) in :class:`http.server.SimpleHTTPRequestHandler`.
..
.. date: 2025-05-16-12-40-37
.. gh-issue: 132124
.. nonce: T_5Odx
.. section: Library
On POSIX-compliant systems, :func:`!multiprocessing.util.get_temp_dir` now
ignores :envvar:`TMPDIR` (and similar environment variables) if the path
length of ``AF_UNIX`` socket files exceeds the platform-specific maximum
length when using the :ref:`forkserver
<multiprocessing-start-method-forkserver>` start method. Patch by Bénédikt
Tran.
..
.. date: 2025-05-15-14-27-01
.. gh-issue: 134062
.. nonce: fRbJet
.. section: Library
:mod:`ipaddress`: fix collisions in :meth:`~object.__hash__` for
:class:`~ipaddress.IPv4Network` and :class:`~ipaddress.IPv6Network` objects.
..
.. date: 2025-05-15-00-27-09
.. gh-issue: 134004
.. nonce: e8k4-R
.. section: Library
:mod:`shelve` as well as underlying :mod:`!dbm.dumb` and :mod:`!dbm.sqlite`
now have :meth:`!reorganize` methods to recover unused free space previously
occupied by deleted entries.
..
.. date: 2025-05-13-18-54-56
.. gh-issue: 133970
.. nonce: 6G-Oi6
.. section: Library
Make :class:`!string.templatelib.Template` and
:class:`!string.templatelib.Interpolation` generic.
..
.. date: 2025-05-13-18-21-59
.. gh-issue: 71253
.. nonce: -3Sf_K
.. section: Library
Raise :exc:`ValueError` in :func:`open` if *opener* returns a negative
file-descriptor in the Python implementation of :mod:`io` to match the C
implementation.
..
.. date: 2025-05-12-20-38-57
.. gh-issue: 133960
.. nonce: Aee79f
.. section: Library
Simplify and improve :func:`typing.evaluate_forward_ref`. It now no longer
raises errors on certain invalid types. In several situations, it is now
able to evaluate forward references that were previously unsupported.
..
.. date: 2025-05-12-06-52-10
.. gh-issue: 133925
.. nonce: elInBY
.. section: Library
Make the private class ``typing._UnionGenericAlias`` hashable.
..
.. date: 2025-05-11-12-56-52
.. gh-issue: 133604
.. nonce: kFxhc8
.. section: Library
Remove :func:`!platform.java_ver` which was deprecated since Python 3.13.
..
.. date: 2025-05-11-11-39-05
.. gh-issue: 133875
.. nonce: pUar3l
.. section: Library
Removed deprecated :meth:`!pathlib.PurePath.is_reserved`. Use
:func:`os.path.isreserved` to detect reserved paths on Windows.
..
.. date: 2025-05-11-10-28-11
.. gh-issue: 133873
.. nonce: H03nov
.. section: Library
Remove the deprecated ``getmark()``, ``setmark()`` and ``getmarkers()``
methods of the :class:`~wave.Wave_read` and :class:`~wave.Wave_write`
classes, which were deprecated since Python 3.13. Patch by Bénédikt Tran.
..
.. date: 2025-05-11-10-01-48
.. gh-issue: 133866
.. nonce: g3dHP_
.. section: Library
Remove the undocumented function :func:`!ctypes.SetPointerType`, which has
been deprecated since Python 3.13. Patch by Bénédikt Tran.
..
.. date: 2025-05-11-08-48-55
.. gh-issue: 133823
.. nonce: F8udQy
.. section: Library
Remove support for ``TD = TypedDict("TD")`` and ``TD = TypedDict("TD",
None)`` calls for constructing :class:`typing.TypedDict` objects with zero
field. Patch by Bénédikt Tran.
..
.. date: 2025-05-10-17-42-03
.. gh-issue: 125996
.. nonce: vaQp0-
.. section: Library
Fix thread safety of :class:`collections.OrderedDict`. Patch by Kumar
Aditya.
..
.. date: 2025-05-10-12-07-54
.. gh-issue: 133817
.. nonce: 4GMtKV
.. section: Library
Remove support for creating :class:`~typing.NamedTuple` classes via the
undocumented keyword argument syntax. Patch by Bénédikt Tran.
..
.. date: 2025-05-10-12-06-55
.. gh-issue: 133653
.. nonce: Gb2aG4
.. section: Library
Fix :class:`argparse.ArgumentParser` with the *formatter_class* argument.
Fix TypeError when *formatter_class* is a custom subclass of
:class:`!HelpFormatter`. Fix TypeError when *formatter_class* is not a
subclass of :class:`!HelpFormatter` and non-standard *prefix_char* is used.
Fix support of colorizing when *formatter_class* is not a subclass of
:class:`!HelpFormatter`.
..
.. date: 2025-05-10-11-04-47
.. gh-issue: 133810
.. nonce: 03WhnK
.. section: Library
Remove :class:`!http.server.CGIHTTPRequestHandler` and ``--cgi`` flag from
the :program:`python -m http.server` command-line interface. They were
deprecated in Python 3.13. Patch by Bénédikt Tran.
..
.. date: 2025-05-09-20-59-24
.. gh-issue: 132641
.. nonce: 3qTw44
.. section: Library
Fixed a race in :func:`functools.lru_cache` under free-threading.
..
.. date: 2025-05-09-19-05-24
.. gh-issue: 133783
.. nonce: 1voCnR
.. section: Library
Fix bug with applying :func:`copy.replace` to :mod:`ast` objects. Attributes
that default to ``None`` were incorrectly treated as required for manually
created AST nodes.
..
.. date: 2025-05-09-18-29-25
.. gh-issue: 133684
.. nonce: Y1DFSt
.. section: Library
Fix bug where :func:`annotationlib.get_annotations` would return the wrong
result for certain classes that are part of a class hierarchy where ``from
__future__ import annotations`` is used.
..
.. date: 2025-05-09-15-50-00
.. gh-issue: 77057
.. nonce: fV8SU-
.. section: Library
Fix handling of invalid markup declarations in
:class:`html.parser.HTMLParser`.
..
.. date: 2025-05-09-09-10-34
.. gh-issue: 130328
.. nonce: s9h4By
.. section: Library
Speedup pasting in ``PyREPL`` on Windows in a legacy console. Patch by Chris
Eibl.
..
.. date: 2025-05-09-08-49-03
.. gh-issue: 133701
.. nonce: KI8tGz
.. section: Library
Fix bug where :class:`typing.TypedDict` classes defined under ``from
__future__ import annotations`` and inheriting from another ``TypedDict``
had an incorrect ``__annotations__`` attribute.
..
.. date: 2025-05-08-20-45-35
.. gh-issue: 133656
.. nonce: cxZODA
.. section: Library
Remove deprecated :meth:`!zipimport.zipimporter.load_module`. Use
:meth:`zipimport.zipimporter.exec_module` instead.
..
.. date: 2025-05-08-20-03-20
.. gh-issue: 133722
.. nonce: 1-B82a
.. section: Library
Added a *color* option to :func:`difflib.unified_diff` that colors output
similar to :program:`git diff`.
..
.. date: 2025-05-08-13-43-19
.. gh-issue: 133489
.. nonce: 9eGS1Z
.. section: Library
:func:`random.getrandbits` can now generate more that 2\ :sup:`31` bits.
:func:`random.randbytes` can now generate more that 256 MiB.
..
.. date: 2025-05-07-22-15-15
.. gh-issue: 133595
.. nonce: c3U88r
.. section: Library
Clean up :class:`sqlite3.Connection` APIs. All parameters of
:func:`sqlite3.connect` except *database* are now keyword-only. The first
three parameters of methods :meth:`~sqlite3.Connection.create_function` and
:meth:`~sqlite3.Connection.create_aggregate` are now positional-only. The
first parameter of methods :meth:`~sqlite3.Connection.set_authorizer`,
:meth:`~sqlite3.Connection.set_progress_handler` and
:meth:`~sqlite3.Connection.set_trace_callback` is now positional-only.
..
.. date: 2025-05-07-19-16-41
.. gh-issue: 133581
.. nonce: kERUCJ
.. section: Library
Improve unparsing of t-strings in :func:`ast.unparse` and ``from __future__
import annotations``. Empty t-strings now round-trip correctly and
formatting in interpolations is preserved. Patch by Jelle Zijlstra.
..
.. date: 2025-05-07-14-36-30
.. gh-issue: 133577
.. nonce: BggPk9
.. section: Library
Add parameter ``formatter`` to :func:`logging.basicConfig`.
..
.. date: 2025-05-07-13-31-06
.. gh-issue: 92897
.. nonce: ubeqGE
.. section: Library
Removed the ``check_home`` parameter from :func:`sysconfig.is_python_build`,
deprecated since Python 3.12.
..
.. date: 2025-05-06-22-54-37
.. gh-issue: 133551
.. nonce: rfy1tJ
.. section: Library
Support t-strings (:pep:`750`) in :mod:`annotationlib`. Patch by Jelle
Zijlstra.
..
.. date: 2025-05-06-14-44-55
.. gh-issue: 133517
.. nonce: Ca6NgW
.. section: Library
Remove :func:`os.listdrives`, :func:`os.listvolumes` and
:func:`os.listmounts` in non Windows desktop builds since the underlying
functionality is missing.
..
.. date: 2025-05-05-22-11-24
.. gh-issue: 133439
.. nonce: LpmyFz
.. section: Library
Fix dot commands with trailing spaces are mistaken for multi-line SQL
statements in the sqlite3 command-line interface.
..
.. date: 2025-05-05-18-50-00
.. gh-issue: 133447
.. nonce: ajshdb
.. section: Library
Add basic color to :mod:`sqlite3` CLI interface.
..
.. date: 2025-05-05-10-41-41
.. gh-issue: 133253
.. nonce: J5-xDD
.. section: Library
Fix thread-safety issues in :mod:`linecache`.
..
.. date: 2025-05-05-03-14-08
.. gh-issue: 133390
.. nonce: AuTggn
.. section: Library
Support keyword completion in the :mod:`sqlite3` command-line interface and
add :data:`sqlite3.SQLITE_KEYWORDS` constant.
..
.. date: 2025-05-04-17-04-55
.. gh-issue: 132493
.. nonce: huirKi
.. section: Library
Avoid accessing ``__annotations__`` unnecessarily in
:func:`inspect.signature`.
..
.. date: 2025-05-01-16-03-11
.. gh-issue: 133017
.. nonce: k7RLQp
.. section: Library
Improve the error message of :func:`multiprocessing.sharedctypes.Array`,
:func:`multiprocessing.sharedctypes.RawArray`,
:func:`multiprocessing.sharedctypes.Value` and
:func:`multiprocessing.sharedctypes.RawValue` when an invalid typecode is
passed. Patch by Tomas Roun
..
.. date: 2025-05-01-10-56-44
.. gh-issue: 132813
.. nonce: rKurvp
.. section: Library
Improve error messages for incorrect types and values of
:class:`csv.Dialect` attributes.
..
.. date: 2025-04-30-19-32-18
.. gh-issue: 132969
.. nonce: EagQ3G
.. section: Library
Prevent the :class:`~concurrent.futures.ProcessPoolExecutor` executor
thread, which remains running when :meth:`shutdown(wait=False)
<concurrent.futures.Executor.shutdown>`, from attempting to adjust the
pool's worker processes after the object state has already been reset during
shutdown. A combination of conditions, including a worker process having
terminated abormally, resulted in an exception and a potential hang when the
still-running executor thread attempted to replace dead workers within the
pool.
..
.. date: 2025-04-29-11-48-46
.. gh-issue: 132876
.. nonce: lyTQGZ
.. section: Library
``ldexp()`` on Windows doesn't round subnormal results before Windows 11,
but should.  Python's :func:`math.ldexp` wrapper now does round them, so
results may change slightly, in rare cases of very small results, on Windows
versions before 11.
..
.. date: 2025-04-26-15-50-12
.. gh-issue: 133009
.. nonce: etBuz5
.. section: Library
:mod:`xml.etree.ElementTree`: Fix a crash in :meth:`Element.__deepcopy__
<object.__deepcopy__>` when the element is concurrently mutated. Patch by
Bénédikt Tran.
..
.. date: 2025-04-25-16-06-53
.. gh-issue: 132908
.. nonce: wV5rja
.. section: Library
Add :func:`math.isnormal` and :func:`math.issubnormal` functions.  Patch by
Sergey B Kirpichev.
..
.. date: 2025-04-25-11-53-37
.. gh-issue: 95380
.. nonce: 7dvPe-
.. section: Library
:func:`fcntl.fcntl` and :func:`fcntl.ioctl`: Remove the 1024 bytes limit on
the size of not mutated bytes-like argument.
..
.. date: 2025-04-25-11-48-00
.. gh-issue: 122781
.. nonce: ajsdns
.. section: Library
Fix ``%z`` directive in :func:`datetime.datetime.strptime` to allow for no
provided offset as was documented.
..
.. date: 2025-04-22-21-00-23
.. gh-issue: 123471
.. nonce: asOLA2
.. section: Library
Make concurrent iterations over :class:`itertools.combinations` and
:class:`itertools.product` safe under free-threading.
..
.. date: 2025-04-21-01-05-14
.. gh-issue: 127081
.. nonce: Egrpq7
.. section: Library
Fix libc thread safety issues with :mod:`dbm` by performing stateful
operations in critical sections.
..
.. date: 2025-04-21-01-03-15
.. gh-issue: 127081
.. nonce: WXRliX
.. section: Library
Fix libc thread safety issues with :mod:`os` by replacing ``getlogin`` with
``getlogin_r`` re-entrant version.
..
.. date: 2025-04-21-00-58-04
.. gh-issue: 127081
.. nonce: 3DCl92
.. section: Library
Fix libc thread safety issues with :mod:`pwd` by locking access to
``getpwall``.
..
.. date: 2025-04-16-21-02-57
.. gh-issue: 132551
.. nonce: Psa7pL
.. section: Library
Make :class:`io.BytesIO` safe in :term:`free-threaded <free threading>`
build.
..
.. date: 2025-04-08-07-25-10
.. gh-issue: 107583
.. nonce: JGfbhq
.. section: Library
Fix :class:`!Flag` inversion when flag set has missing values
(:class:`!IntFlag` still flips all bits); fix negative assigned values
during flag creation (both :class:`!Flag` and :class:`!IntFlag` ignore
missing values).
..
.. date: 2025-04-07-10-20-16
.. gh-issue: 87790
.. nonce: X2SjJe
.. section: Library
Support underscore and comma as thousands separators in the fractional part
for :class:`~fractions.Fraction`'s formatting.  Patch by Sergey B Kirpichev.
..
.. date: 2025-04-07-09-53-54
.. gh-issue: 87790
.. nonce: 6nj3zQ
.. section: Library
Support underscore and comma as thousands separators in the fractional part
for :class:`~decimal.Decimal`'s formatting.  Patch by Sergey B Kirpichev.
..
.. date: 2025-04-07-06-41-54
.. gh-issue: 131884
.. nonce: ym9BJN
.. section: Library
Fix formatting issues in :func:`json.dump` when both *indent* and *skipkeys*
are used.
..
.. date: 2025-03-27-08-13-32
.. gh-issue: 131788
.. nonce: 0RWiFc
.. section: Library
Make ``ResourceTracker.send`` from :mod:`multiprocessing` re-entrant safe
..
.. date: 2025-03-19-12-41-42
.. gh-issue: 91349
.. nonce: 8eTOCP
.. section: Library
Adjust default ``compressionlevel=`` to 6 (down from 9) in :mod:`gzip` and
:mod:`tarfile`. It is the default level used by most compression tools and a
better tradeoff between speed and performance.
..
.. date: 2025-03-17-21-21-06
.. gh-issue: 131146
.. nonce: A5Obgv
.. section: Library
Fix :class:`calendar.TextCalendar`, :class:`calendar.HTMLCalendar`, and the
:mod:`calendar` CLI to display month names in the nominative case by adding
:data:`calendar.standalone_month_name` and
:data:`calendar.standalone_month_abbr`, which provide month names and
abbreviations in the grammatical form used when a month name stands by
itself, if the locale supports it.
..
.. date: 2025-03-13-20-48-58
.. gh-issue: 123471
.. nonce: cM4w4f
.. section: Library
Make concurrent iterations over :class:`itertools.cycle` safe under
free-threading.
..
.. date: 2025-03-11-05-24-14
.. gh-issue: 130664
.. nonce: g0yNMm
.. section: Library
Handle corner-case for :class:`~fractions.Fraction`'s formatting: treat
zero-padding (preceding the width field by a zero (``'0'``) character) as an
equivalent to a fill character of ``'0'`` with an alignment type of ``'='``,
just as in case of :class:`float`'s.
..
.. date: 2025-03-09-03-13-41
.. gh-issue: 130999
.. nonce: tBRBVB
.. section: Library
Avoid exiting the new REPL and offer suggestions even if there are
non-string candidates when errors occur.
..
.. date: 2025-03-08-17-07-00
.. gh-issue: 88473
.. nonce: qg23g8
.. section: Library
Implement a fast path for :class:`datetime.date` objects in
:func:`datetime.date.today` which results in a 5x performance gain while
proper subclasses retain their previous performance.
..
.. date: 2024-11-25-10-22-08
.. gh-issue: 126883
.. nonce: MAEF7g
.. section: Library
Add check that timezone fields are in range for
:meth:`datetime.datetime.fromisoformat` and
:meth:`datetime.time.fromisoformat`. Patch by Semyon Moroz.
..
.. date: 2024-10-28-06-54-22
.. gh-issue: 125028
.. nonce: GEY8Ws
.. section: Library
:data:`functools.Placeholder` cannot be passed to :func:`functools.partial`
as a keyword argument.
..
.. date: 2024-10-22-16-21-55
.. gh-issue: 125843
.. nonce: 2ttzYo
.. section: Library
If possible, indicate which :mod:`curses` C function or macro is responsible
for raising a :exc:`curses.error` exception. Patch by Bénédikt Tran.
..
.. date: 2024-10-17-01-12-22
.. gh-issue: 119109
.. nonce: u4hcvb
.. section: Library
:func:`functools.partial` calls are now faster when keyword arguments are
used.
..
.. date: 2024-09-13-09-48-25
.. gh-issue: 124033
.. nonce: WNudS0
.. section: Library
``SimplePath`` is now presented in ``importlib.metadata.__all__``.
..
.. date: 2024-09-13-09-46-47
.. gh-issue: 91216
.. nonce: LuOsF4
.. section: Library
``importlib.metadata`` now raises a ``KeyError`` instead of returning
``None`` when a key is missing from the metadata.
..
.. date: 2024-09-13-09-43-15
.. gh-issue: 120492
.. nonce: Mm6CJ6
.. section: Library
``importlib.metadata`` now prioritizes valid dists to invalid dists when
retrieving by name.
..
.. date: 2024-07-16-00-01-04
.. gh-issue: 99631
.. nonce: GWD4fD
.. section: Library
The :mod:`shelve` module now accepts custom serialization and
deserialization functions.
..
.. date: 2024-07-06-14-32-30
.. gh-issue: 119186
.. nonce: E5B1HQ
.. section: Library
Slightly speed up :func:`os.walk` by calling :func:`os.path.join` less
often.
..
.. date: 2024-06-06-17-49-07
.. gh-issue: 120170
.. nonce: DUxhmT
.. section: Library
Fix an issue in the :mod:`!_pickle` extension module in which importing
:mod:`multiprocessing` could change how pickle identifies which module an
object belongs to, potentially breaking the unpickling of those objects.
..
.. date: 2024-05-13-09-50-31
.. gh-issue: 118981
.. nonce: zgOQPv
.. section: Library
Fix potential hang in ``multiprocessing.popen_spawn_posix`` that can happen
when the child proc dies early by closing the child fds right away.
..
.. date: 2023-07-05-14-34-10
.. gh-issue: 105497
.. nonce: HU5u89
.. section: Library
Fix flag mask inversion when unnamed flags exist.
..
.. date: 2023-03-13-22-51-40
.. gh-issue: 99813
.. nonce: 40TV02
.. section: Library
:mod:`ssl` now uses ``SSL_sendfile`` internally when it is possible (see
:data:`~ssl.OP_ENABLE_KTLS`). The function sends a file more efficiently
because it performs TLS encryption in the kernel to avoid additional context
switches. Patch by Illia Volochii.
..
.. date: 2023-02-13-21-56-38
.. gh-issue: 62824
.. nonce: CBZzX3
.. section: Library
Fix aliases for ``iso8859_8`` encoding. Patch by Dave Goncalves.
..
.. date: 2023-02-13-21-41-34
.. gh-issue: 86155
.. nonce: ppIGSC
.. section: Library
:meth:`html.parser.HTMLParser.close` no longer loses data when the
``<script>`` tag is not closed. Patch by Waylan Limberg.
..
.. date: 2023-02-13-20-34-52
.. gh-issue: 78319
.. nonce: V1zzed
.. section: Library
UTF8 support for the IMAP APPEND command has been made RFC compliant.
..
.. date: 2022-10-08-14-56-07
.. gh-issue: 93334
.. nonce: 0KUm8d
.. section: Library
Reraise :exc:`KeyError` as :exc:`ModuleNotFoundError` when
:meth:`importlib.machinery.PathFinder.find_spec` is called on a submodule
without importing the parent (and without a ``path`` argument).
..
.. date: 2022-07-24-20-56-32
.. gh-issue: 69426
.. nonce: unccw7
.. section: Library
Fix :class:`html.parser.HTMLParser` to not unescape character entities in
attribute values if they are followed by an ASCII alphanumeric or an equals
sign.
..
.. bpo: 38735
.. date: 2022-01-07-16-56-57
.. nonce: NFfJX6
.. section: Library
Fix failure when importing a module from the root directory on unix-like
platforms with sys.pycache_prefix set.
..
.. bpo: 45959
.. date: 2021-12-18-12-46-20
.. nonce: vPlr3P
.. section: Library
:mod:`pprint` can now pretty-print dict views.
..
.. date: 2021-09-21-17-17-29
.. gh-issue: 84683
.. nonce: wDSRsG
.. section: Library
:mod:`zoneinfo`: Check in ``<prefix>/share/zoneinfo`` for data files on
Windows
..
.. bpo: 43429
.. date: 2021-03-07-16-31-36
.. nonce: Koa0mf
.. section: Library
The :meth:`~mmap.mmap.size` method of the :class:`mmap.mmap` class now
returns the size of an anonymous mapping on both Unix and Windows.
Previously, the size would be returned on Windows and an :exc:`OSError`
would be raised on Unix. :exc:`ValueError` is now raised instead of
:exc:`OSError` when ``trackfd=False``.
..
.. bpo: 41839
.. date: 2020-09-23-11-54-17
.. nonce: kU5Ywl
.. section: Library
Allow negative priority values from :func:`os.sched_get_priority_min` and
:func:`os.sched_get_priority_max` functions.
..
.. bpo: 28494
.. date: 2017-12-30-18-21-00
.. nonce: Dt_Wks
.. section: Library
Improve Zip file validation false positive rate in
:func:`zipfile.is_zipfile`.
..
.. date: 2025-10-09-12-53-47
.. gh-issue: 96491
.. nonce: 4YKxvy
.. section: IDLE
Deduplicate version number in IDLE shell title bar after saving to a file.
..
.. date: 2025-10-08-08-35-50
.. gh-issue: 139742
.. nonce: B3fZLg
.. section: IDLE
Colorize t-string prefixes for template strings in IDLE, as done for
f-string prefixes.
..
.. date: 2025-07-01-23-00-58
.. gh-issue: 136155
.. nonce: 4siQQO
.. section: Documentation
We are now checking for fatal errors in EPUB builds in CI.
..
.. date: 2025-06-10-17-02-06
.. gh-issue: 135171
.. nonce: quHvts
.. section: Documentation
Document that the :term:`iterator` for the leftmost :keyword:`!for` clause
in the generator expression is created immediately.
..
.. bpo: 45210
.. date: 2021-09-15-13-07-25
.. nonce: RtGk7i
.. section: Documentation
Document that error indicator may be set in tp_dealloc, and how to avoid
clobbering it.
..
.. date: 2025-10-13-17-56-23
.. gh-issue: 140000
.. nonce: tLhn3e
.. section: Core and Builtins
Fix potential memory leak when a reference cycle exists between an instance
of :class:`typing.TypeAliasType`, :class:`typing.TypeVar`,
:class:`typing.ParamSpec`, or :class:`typing.TypeVarTuple` and its
``__name__`` attribute. Patch by Mikhail Efimov.
..
.. date: 2025-10-12-18-54-06
.. gh-issue: 140009
.. nonce: -MbFh_
.. section: Core and Builtins
Improve performance of list extension by dictionary items.
..
.. date: 2025-10-12-11-00-06
.. gh-issue: 139988
.. nonce: 4wi51t
.. section: Core and Builtins
Fix a memory leak when failing to create a :class:`~typing.Union` type.
Patch by Bénédikt Tran.
..
.. date: 2025-10-08-13-52-00
.. gh-issue: 139748
.. nonce: jq0yFJ
.. section: Core and Builtins
Fix reference leaks in error branches of functions accepting path strings or
bytes such as :func:`compile` and :func:`os.system`. Patch by Bénédikt Tran.
..
.. date: 2025-10-06-13-15-26
.. gh-issue: 139516
.. nonce: d9Pkur
.. section: Core and Builtins
Fix lambda colon erroneously start format spec in f-string in tokenizer.
..
.. date: 2025-10-01-18-21-19
.. gh-issue: 63161
.. nonce: ef1S6N
.. section: Core and Builtins
Support non-UTF-8 shebang and comments in Python source files if non-UTF-8
encoding is specified. Detect decoding error in comments for default (UTF-8)
encoding. Show the line and position of decoding error for default encoding
in a traceback. Show the line containing the coding cookie when it conflicts
with the BOM in a traceback.
..
.. date: 2025-09-30-14-57-19
.. gh-issue: 139116
.. nonce: nlVf40
.. section: Core and Builtins
Prevent a deadlock when multiple threads start, stop and use
:mod:`tracemalloc` simultaneously.
..
.. date: 2025-09-24-17-32-52
.. gh-issue: 139275
.. nonce: novrqf
.. section: Core and Builtins
Fix compilation problems in ``_remote_debugging_module.c`` when the system
doesn't have ``process_vm_readv``. Patch by Pablo Galindo
..
.. date: 2025-09-24-17-08-42
.. gh-issue: 133059
.. nonce: EXvxb7
.. section: Core and Builtins
Increased the number of cached small positive integers from 256 to 1024.
..
.. date: 2025-09-22-15-21-49
.. gh-issue: 74857
.. nonce: 5XRQaA
.. section: Core and Builtins
:pep:`538`: Coerce the POSIX locale to a UTF-8 based locale. Patch by Victor
Stinner.
..
.. date: 2025-09-21-14-33-17
.. gh-issue: 116738
.. nonce: vNaI4h
.. section: Library
Make :mod:`mmap` thread-safe on the :term:`free threaded <free threading>`
build.
..
.. date: 2025-09-17-17-17-21
.. gh-issue: 138558
.. nonce: 0VbzCH
.. section: Core and Builtins
Fix handling of unusual t-string annotations in annotationlib. Patch by Dave
Peck.
..
.. date: 2025-09-15-14-04-56
.. gh-issue: 134466
.. nonce: yR4fYW
.. section: Core and Builtins
Don't run PyREPL in a degraded environment where setting termios attributes
is not allowed.
..
.. date: 2025-09-11-15-56-18
.. gh-issue: 138794
.. nonce: nrOn1K
.. section: Core and Builtins
When a new tracing function is registered with
:c:func:`PyRefTracer_SetTracer`,  replacing the current a call to the trace
function will be made with the object set to **NULL** and **event** set to
:c:data:`PyRefTracer_TRACKER_REMOVED`. This will happen just before the new
function is registered. Patch by Pablo Galindo
..
.. date: 2025-09-10-14-53-59
.. gh-issue: 71810
.. nonce: ppf0J-
.. section: Core and Builtins
Raise :exc:`OverflowError` for ``(-1).to_bytes()`` for signed conversions
when bytes count is zero.  Patch by Sergey B Kirpichev.
..
.. date: 2025-09-09-23-59-13
.. gh-issue: 138716
.. nonce: UawDY0
.. section: Core and Builtins
Improve :exc:`SyntaxError` message for :keyword:`assert` in cases like
``assert a := b``.
..
.. date: 2025-09-06-13-53-33
.. gh-issue: 105487
.. nonce: a43YaY
.. section: Core and Builtins
Remove non-existent :meth:`~object.__copy__`, :meth:`~object.__deepcopy__`,
and :attr:`~type.__bases__` from the :meth:`~object.__dir__` entries of
:class:`types.GenericAlias`.
..
.. date: 2025-09-05-01-19-04
.. gh-issue: 138192
.. nonce: erluq5
.. section: Core and Builtins
Fix :mod:`contextvars` initialization so that all subinterpreters are
assigned the :attr:`~contextvars.Token.MISSING` value.
..
.. date: 2025-09-03-17-00-30
.. gh-issue: 138479
.. nonce: qUxgWs
.. section: Core and Builtins
Fix a crash when a generic object's ``__typing_subst__`` returns an object
that isn't a :class:`tuple`.
..
.. date: 2025-09-03-15-35-34
.. gh-issue: 138431
.. nonce: EUsrtA
.. section: Core and Builtins
Fix a bug in the JIT optimizer when round-tripping strings and tuples.
..
.. date: 2025-09-03-10-16-09
.. gh-issue: 138378
.. nonce: r6BQxV
.. section: Core and Builtins
Move the globals-to-const JIT optimizer pass into to the main JIT optimizer
pass
..
.. date: 2025-09-02-22-17-55
.. gh-issue: 138401
.. nonce: uTRvue
.. section: Library
Add missing validation of argument ``count`` in :func:`os.sendfile` to be
non-negative.
..
.. date: 2025-09-02-09-10-06
.. gh-issue: 138372
.. nonce: h1Xk4-
.. section: Core and Builtins
Fix :exc:`SyntaxWarning` emitted for erroneous subscript expressions
involving :ref:`template string literals <t-strings>`. Patch by Brian
Schubert.
..
.. date: 2025-09-01-21-52-54
.. gh-issue: 138302
.. nonce: -ez47B
.. section: Core and Builtins
``BINARY_OP`` now specializes to ``BINARY_OP_ADD_INT``,
``BINARY_OP_SUBTRACT_INT`` or ``BINARY_OP_MULTIPLY_INT`` if operands are
compact ints.
..
.. date: 2025-09-01-16-09-02
.. gh-issue: 138318
.. nonce: t-WEN5
.. section: Core and Builtins
The default REPL now avoids highlighting built-in names (for instance
:class:`set` or :func:`format`) when they are used as attribute names (for
instance in ``value.set`` or ``text.format``).
..
.. date: 2025-09-01-13-54-43
.. gh-issue: 138349
.. nonce: 0fGmAi
.. section: Core and Builtins
Fix crash in certain cases where a module contains both a module-level
annotation and a comprehension.
..
.. date: 2025-08-30-17-15-05
.. gh-issue: 69605
.. nonce: KjBk99
.. section: Core and Builtins
Fix some standard library submodules missing from the :term:`REPL`
auto-completion of imports.
..
.. date: 2025-08-30-00-55-35
.. gh-issue: 61206
.. nonce: HeFLvl
.. section: Core and Builtins
:mod:`zipimport` now supports zstandard compressed zip file entries.
..
.. date: 2025-08-28-09-29-46
.. gh-issue: 116738
.. nonce: yLZJpV
.. section: Library
Make :mod:`!cProfile` thread-safe on the :term:`free threaded <free
threading>` build.
..
.. date: 2025-08-27-17-51-38
.. gh-issue: 137838
.. nonce: lK6T0j
.. section: Core and Builtins
Fix JIT trace buffer overrun by increasing possible exit stubs. Patch by
Donghee Na.
..
.. date: 2025-08-27-13-11-47
.. gh-issue: 71679
.. nonce: V0yFeT
.. section: Core and Builtins
Use the same quoting algorithm for the repr of bytearrays as for bytes
objects and strings -- use double quotes for quoting if the bytearray
contains single quotes and does not contain double quotes.
..
.. date: 2025-08-22-11-39-40
.. gh-issue: 137384
.. nonce: j4b_in
.. section: Core and Builtins
Fix a crash when using the :mod:`warnings` module in a finalizer at
shutdown. Patch by Kumar Aditya.
..
.. date: 2025-08-21-06-31-42
.. gh-issue: 138004
.. nonce: FH2Hre
.. section: Library
On Solaris/Illumos platforms, thread names are now encoded as ASCII to avoid
errors on systems (e.g. OpenIndiana) that don't support non-ASCII names.
..
.. date: 2025-08-21-01-46-39
.. gh-issue: 137976
.. nonce: p4sb4x
.. section: Library
Removed ``localtime`` from the list of reported system timezones.
..
.. date: 2025-08-20-14-17-47
.. gh-issue: 137992
.. nonce: fcL3SK
.. section: Core and Builtins
Ensure that  :c:func:`PyRefTracer_SetTracer` sync with all existing threads
when called to avoid races in the free threaded build. Patch by Pablo
Galindo
..
.. date: 2025-08-19-18-52-22
.. gh-issue: 137967
.. nonce: uw67Ys
.. section: Core and Builtins
Show error suggestions on nested attribute access. Patch by Pablo Galindo
..
.. date: 2025-08-19-16-07-07
.. gh-issue: 137959
.. nonce: EWj0RZ
.. section: Core and Builtins
Replace the shim code added to every piece of jitted code with a single
trampoline function.
..
.. date: 2025-08-17-13-36-53
.. gh-issue: 137883
.. nonce: 55VDCN
.. section: Core and Builtins
Fix runaway recursion when calling a function with keyword arguments.
..
.. date: 2025-08-15-15-45-26
.. gh-issue: 137079
.. nonce: YEow69
.. section: Core and Builtins
Fix keyword typo recognition when parsing files. Patch by Pablo Galindo.
..
.. date: 2025-08-14-14-18-29
.. gh-issue: 137728
.. nonce: HdYS9R
.. section: Core and Builtins
Fix the JIT's handling of many local variables. This previously caused a
segfault.
..
.. date: 2025-08-13-16-58-58
.. gh-issue: 137716
.. nonce: ZcZSyi
.. section: Core and Builtins
Fix double period in :exc:`AttributeError` message for invalid mock
assertions
..
.. date: 2025-08-13-13-39-02
.. gh-issue: 137433
.. nonce: g6Atfz
.. section: Core and Builtins
Fix a potential deadlock in the :term:`free threading` build when daemon
threads enable or disable profiling or tracing while the main thread is
shutting down the interpreter.
..
.. date: 2025-08-10-21-34-12
.. gh-issue: 137576
.. nonce: 0ZicS-
.. section: Core and Builtins
Fix for incorrect source code being shown in tracebacks from the Basic REPL
when :envvar:`PYTHONSTARTUP` is given. Patch by Adam Hartz.
..
.. date: 2025-08-09-11-38-37
.. gh-issue: 37817
.. nonce: Y5Fhde
.. section: Core and Builtins
Allow assignment to :attr:`~type.__bases__` of direct subclasses of builtin
classes.
..
.. date: 2025-08-09-04-07-05
.. gh-issue: 132732
.. nonce: 8BiIVJ
.. section: Core and Builtins
Optimize ``_COMPARE_OP``, ``_CONTAINS_OP``, ``_UNARY_NEGATIVE``,
``_UNARY_NOT``, and ``_UNARY_INVERT`` in JIT builds with constant-loading
uops (``_POP_TWO_LOAD_CONST_INLINE_BORROW`` and
``_POP_TOP_LOAD_CONST_INLINE_BORROW``), and then remove both to reduce
instruction count.
..
.. date: 2025-08-07-09-52-19
.. gh-issue: 137400
.. nonce: AK1dy-
.. section: Core and Builtins
Fix a crash in the :term:`free threading` build when disabling profiling or
tracing across all threads with :c:func:`PyEval_SetProfileAllThreads` or
:c:func:`PyEval_SetTraceAllThreads` or their Python equivalents
:func:`threading.settrace_all_threads` and
:func:`threading.setprofile_all_threads`.
..
.. date: 2025-08-06-16-55-44
.. gh-issue: 133143
.. nonce: l7CI9v
.. section: Core and Builtins
Add :data:`sys.abi_info` object to make ABI information more easily
accessible.
..
.. date: 2025-08-06-15-39-54
.. gh-issue: 137400
.. nonce: xIw0zs
.. section: Core and Builtins
Fix a crash in the :term:`free threading` build when disabling profiling or
tracing across all threads with :c:func:`PyEval_SetProfileAllThreads` or
:c:func:`PyEval_SetTraceAllThreads` or their Python equivalents
:func:`threading.settrace_all_threads` and
:func:`threading.setprofile_all_threads`.
..
.. date: 2025-08-05-20-24-12
.. gh-issue: 120037
.. nonce: MB7MmI
.. section: Core and Builtins
Disable user site packages directory when a ``._pth`` file is used, even if
it contains ``import site``.
..
.. date: 2025-08-05-17-22-24
.. gh-issue: 58124
.. nonce: q1__53
.. section: Core and Builtins
Fix name of the Python encoding in Unicode errors of the code page codec:
use "cp65000" and "cp65001" instead of "CP_UTF7" and "CP_UTF8" which are not
valid Python code names. Patch by Victor Stinner.
..
.. date: 2025-08-05-10-22-15
.. gh-issue: 136966
.. nonce: J5lrE0
.. section: Core and Builtins
The :attr:`object.__dict__` and :attr:`!__weakref__` descriptors now use a
single descriptor instance per interpreter, shared across all types that
need them. This speeds up class creation, and helps avoid reference cycles.
..
.. date: 2025-08-02-23-04-57
.. gh-issue: 137314
.. nonce: wjEdzD
.. section: Core and Builtins
Fixed a regression where raw f-strings incorrectly interpreted escape
sequences in format specifications. Raw f-strings now properly preserve
literal backslashes in format specs, matching the behavior from Python 3.11.
For example, ``rf"{obj:\xFF}"`` now correctly produces ``'\\xFF'`` instead
of ``'ÿ'``. Patch by Pablo Galindo.
..
.. date: 2025-08-02-10-27-53
.. gh-issue: 137308
.. nonce: at05p_
.. section: Core and Builtins
A standalone docstring in a node body is optimized as a :keyword:`pass`
statement to ensure that the node's body is never empty. There was a
:exc:`ValueError` in :func:`compile` otherwise.
..
.. date: 2025-08-01-18-54-31
.. gh-issue: 137288
.. nonce: FhE7ku
.. section: Core and Builtins
Fix bug where some bytecode instructions of a boolean expression are not
associated with the correct exception handler.
..
.. date: 2025-07-31-23-02-02
.. gh-issue: 137291
.. nonce: kIxVZd
.. section: Core and Builtins
The perf profiler can now be used if a previous frame evaluation API has
been provided.
..
.. date: 2025-07-28-19-11-34
.. gh-issue: 134291
.. nonce: IiB9Id
.. section: Core and Builtins
Remove some newer macOS API usage from the JIT compiler in order to restore
compatibility with older OSX 10.15 deployment targets.
..
.. date: 2025-07-28-17-01-05
.. gh-issue: 88886
.. nonce: g4XFPb
.. section: Core and Builtins
The codecs lookup function now again performs only minimal normalization of
the encoding name before passing it to the search functions: all ASCII
letters are converted to lower case, spaces are replaced with hyphens. This
restores the pre-Python 3.9 behavior.
..
.. date: 2025-07-25-22-31-52
.. gh-issue: 131338
.. nonce: zJDCMp
.. section: Core and Builtins
Disable computed stack limit checks on non-glibc linux platforms to fix
crashes on deep recursion.
..
.. date: 2025-07-24-17-30-58
.. gh-issue: 136870
.. nonce: ncx82J
.. section: Core and Builtins
Fix data races while de-instrumenting bytecode of code objects running
concurrently in threads.
..
.. date: 2025-07-24-02-13-59
.. gh-issue: 132732
.. nonce: p77xkb
.. section: Core and Builtins
Optimize constant comparison for ``_COMPARE_OP_INT``, ``_COMPARE_OP_FLOAT``
and ``_COMPARE_OP_STR`` in JIT builds
..
.. date: 2025-07-19-17-08-09
.. gh-issue: 127598
.. nonce: Mx8S-y
.. section: Core and Builtins
Improve :exc:`ModuleNotFoundError` by adding flavour text to the exception
when the :option:`-S` option is passed. Patch by Andrea Mattei.
..
.. date: 2025-07-19-12-37-05
.. gh-issue: 136801
.. nonce: XU_tF2
.. section: Core and Builtins
Fix PyREPL syntax highlighting on match cases after multi-line case.
Contributed by Olga Matoula.
..
.. date: 2025-07-19-10-35-31
.. gh-issue: 74185
.. nonce: 7hPCA5
.. section: Core and Builtins
The :meth:`~object.__repr__` of :class:`ImportError` and
:class:`ModuleNotFoundError` now shows "name" and "path" as ``name=<name>``
and ``path=<path>`` if they were given as keyword arguments at construction
time. Patch by Serhiy Storchaka, Oleg Iarygin, and Yoav Nir
..
.. date: 2025-07-18-08-43-35
.. gh-issue: 116738
.. nonce: i0HWtP
.. section: Library
Make functions in :mod:`syslog` thread-safe on the :term:`free threaded
<free threading>` build.
..
.. date: 2025-07-15-10-03-57
.. gh-issue: 116738
.. nonce: oFttKl
.. section: Library
Make functions in :mod:`pwd` thread-safe on the :term:`free threaded <free
threading>` build.
..
.. date: 2025-07-14-17-01-23
.. gh-issue: 136616
.. nonce: FQjXE_
.. section: Core and Builtins
Improve :exc:`SyntaxError` error messages for invalid :keyword:`assert`
usages.
..
.. date: 2025-07-13-21-21-17
.. gh-issue: 136599
.. nonce: sLhm2O
.. section: Core and Builtins
Improve performance of :class:`int` hash calculations.
..
.. date: 2025-07-12-09-59-14
.. gh-issue: 136421
.. nonce: ZD1rNj
.. section: Library
Fix crash when initializing :mod:`datetime` concurrently.
..
.. date: 2025-07-11-13-45-48
.. gh-issue: 136541
.. nonce: uZ_-Ju
.. section: Core and Builtins
Fix some issues with the perf trampolines on x86-64 and aarch64.  The
trampolines were not being generated correctly for some cases, which could
lead to the perf integration not working correctly. Patch by Pablo Galindo.
..
.. date: 2025-07-11-12-29-09
.. gh-issue: 107545
.. nonce: ipfl7U
.. section: Library
Improve the error messages that may be raised by
:meth:`~socket.socket.setsockopt`.
..
.. date: 2025-07-10-23-23-50
.. gh-issue: 136517
.. nonce: _NHJyv
.. section: Core and Builtins
Fixed a typo that prevented printing of uncollectable objects when the
:const:`gc.DEBUG_UNCOLLECTABLE` mode was set.
..
.. date: 2025-07-10-15-53-16
.. gh-issue: 136525
.. nonce: xAko0e
.. section: Core and Builtins
Fix issue where per-thread bytecode was not instrumented for newly created
threads.
..
.. date: 2025-07-09-21-27-14
.. gh-issue: 132657
.. nonce: kSA8R3
.. section: Core and Builtins
Improve performance of :class:`frozenset` by removing locks in the
free-threading build.
..
.. date: 2025-07-09-11-15-42
.. gh-issue: 136459
.. nonce: m4Udh8
.. section: Core and Builtins
Add support for perf trampoline on macOS, to allow profilers wit JIT map
support to read Python calls. While profiling, ``PYTHONPERFSUPPORT=1`` can
be appended to enable the trampoline.
..
.. date: 2025-07-08-23-53-51
.. gh-issue: 132661
.. nonce: B84iYt
.. section: Core and Builtins
``Interpolation.expression`` now has a default, the empty string.
..
.. date: 2025-07-08-23-22-08
.. gh-issue: 132661
.. nonce: 34ftJl
.. section: Core and Builtins
Reflect recent :pep:`750` change.
Disallow concatenation of ``string.templatelib.Template`` and :class:`str`.
Also, disallow implicit concatenation of t-string literals with string or
f-string literals.
..
.. date: 2025-07-07-17-26-06
.. gh-issue: 91636
.. nonce: GyHU72
.. section: Core and Builtins
While performing garbage collection, clear weakrefs to unreachable objects
that are created during running of finalizers.  If those weakrefs were are
not cleared, they could reveal unreachable objects.
..
.. date: 2025-07-07-12-24-00
.. gh-issue: 136355
.. nonce: MTcA8j
.. section: Core and Builtins
Deprecate :option:`-b` and :option:`!-bb` command line options and schedule
them to become no-op in Python 3.17.
..
.. date: 2025-07-06-14-53-19
.. gh-issue: 109700
.. nonce: KVNQQi
.. section: Core and Builtins
Fix memory error handling in :c:func:`PyDict_SetDefault`.
..
.. date: 2025-07-03-06-04-42
.. gh-issue: 135552
.. nonce: CbBQof
.. section: Core and Builtins
Fix a bug caused by the garbage collector clearing weakrefs too early.  The
weakrefs in the ``tp_subclasses`` dictionary are needed in order to
correctly invalidate type caches (for example, by calling
``PyType_Modified()``). Clearing weakrefs before calling finalizers causes
the caches to not be correctly invalidated.  That can cause crashes since
the caches can refer to invalid objects.  Defer the clearing of weakrefs
without callbacks until after finalizers are executed.
..
.. date: 2025-07-02-15-18-41
.. gh-issue: 136203
.. nonce: Y934sC
.. section: Core and Builtins
Improve :exc:`TypeError` error message, when richcomparing two
:class:`types.MappingProxyType` objects.
..
.. date: 2025-06-26-18-44-34
.. gh-issue: 136003
.. nonce: sln51d
.. section: Core and Builtins
Fix :class:`threading.Thread` objects becoming incorrectly daemon when
created from an :mod:`atexit` callback or a pending call
(:c:func:`Py_AddPendingCall`).
..
.. date: 2025-06-26-15-25-51
.. gh-issue: 78465
.. nonce: MbDN8X
.. section: Core and Builtins
Fix error message for ``cls.__new__(cls, ...)`` where ``cls`` is not
instantiable builtin or extension type (with ``tp_new`` set to ``NULL``).
..
.. date: 2025-06-24-16-46-34
.. gh-issue: 135904
.. nonce: 78xfon
.. section: Core and Builtins
Perform more aggressive control-flow optimizations on the machine code
templates emitted by the experimental JIT compiler.
..
.. date: 2025-06-24-06-41-47
.. gh-issue: 129958
.. nonce: EaJuS0
.. section: Core and Builtins
Differentiate between t-strings and f-strings in syntax error for newlines
in format specifiers of single-quoted interpolated strings.
..
.. date: 2025-06-23-18-08-32
.. gh-issue: 135871
.. nonce: 50C528
.. section: Core and Builtins
Non-blocking mutex lock attempts now return immediately when the lock is
busy instead of briefly spinning in the :term:`free threading` build.
..
.. date: 2025-06-20-14-50-44
.. gh-issue: 134584
.. nonce: 3CJdAI
.. section: Core and Builtins
Specialize :opcode:`POP_TOP` in the JIT compiler by specializing for
reference lifetime and type. This will also enable easier top of stack
caching in the JIT compiler.
..
.. date: 2025-06-18-16-45-36
.. gh-issue: 135106
.. nonce: cpl6Aq
.. section: Core and Builtins
Restrict the trashcan mechanism to GC'ed objects and untrack them while in
the trashcan to prevent the GC and trashcan mechanisms conflicting.
..
.. date: 2025-06-18-12-19-13
.. gh-issue: 135379
.. nonce: TCvGpj
.. section: Core and Builtins
Changes specialization of ``BINARY_OP`` for ints to only specialize for
"compact" ints. This streamlines the fast path at the cost of fewer
specializations when very large integers are used.
..
.. date: 2025-06-17-22-34-58
.. gh-issue: 135607
.. nonce: ucsLVu
.. section: Core and Builtins
Fix potential :mod:`weakref` races in an object's destructor on the
:term:`free threaded <free threading>` build.
..
.. date: 2025-06-17-12-50-48
.. gh-issue: 135608
.. nonce: PnHckD
.. section: Core and Builtins
Fix a crash in the JIT involving attributes of modules.
..
.. date: 2025-06-17-08-37-45
.. gh-issue: 82088
.. nonce: TgPvLg
.. section: Core and Builtins
Improve performance of ``PyLongObject`` conversion functions
``PyLong_AsLongAndOverflow()``, ``PyLong_AsSsize_t()``,
``PyLong_AsUnsignedLong()``, ``PyLong_AsSize_t()``,
``PyLong_AsUnsignedLongMask()``, ``PyLong_AsUnsignedLongLongMask()``,
``PyLong_AsLongLongAndOverflow()`` for integers larger than 2**30 up to 30%.
..
.. date: 2025-06-16-03-56-15
.. gh-issue: 135551
.. nonce: hRTQO-
.. section: Core and Builtins
Sorting randomly ordered lists will often run a bit faster, thanks to a new
scheme for picking minimum run lengths from Stefan Pochmann, which arranges
for the merge tree to be as evenly balanced as is possible.
..
.. date: 2025-06-16-02-31-42
.. gh-issue: 135543
.. nonce: 6b0HOF
.. section: Core and Builtins
Emit ``sys.remote_exec`` audit event when :func:`sys.remote_exec` is called
and migrate ``remote_debugger_script`` to
``cpython.remote_debugger_script``.
..
.. date: 2025-06-14-01-01-14
.. gh-issue: 135496
.. nonce: ER0Me3
.. section: Core and Builtins
Fix typo in the f-string conversion type error ("exclamanation" ->
"exclamation").
..
.. date: 2025-06-13-16-05-24
.. gh-issue: 135474
.. nonce: 67nOl3
.. section: Core and Builtins
Specialize integer operations only on compact integers. This is a CPython
internal change.
..
.. date: 2025-06-12-18-12-42
.. gh-issue: 135371
.. nonce: R_YUtR
.. section: Core and Builtins
Fixed :mod:`asyncio` debugging tools to properly display internal coroutine
call stacks alongside external task dependencies. The ``python -m asyncio
ps`` and ``python -m asyncio pstree`` commands now show complete execution
context. Patch by Pablo Galindo.
..
.. date: 2025-06-12-11-19-52
.. gh-issue: 135422
.. nonce: F6yQi6
.. section: Core and Builtins
Fix regression in :exc:`SyntaxError` messages after :gh:`134036`.
..
.. date: 2025-06-12-00-03-34
.. gh-issue: 116738
.. nonce: iBBAdo
.. section: Library
Make functions in :mod:`grp` thread-safe on the :term:`free threaded <free
threading>` build.
..
.. date: 2025-06-11-15-08-10
.. gh-issue: 127319
.. nonce: OVGFSZ
.. section: Library
Set the ``allow_reuse_port`` class variable to ``False`` on the XMLRPC,
logging, and HTTP servers. This matches the behavior in prior Python
releases, which is to not allow port reuse.
..
.. date: 2025-06-09-23-57-37
.. gh-issue: 130077
.. nonce: MHknDB
.. section: Core and Builtins
Properly raise custom syntax errors when incorrect syntax containing names
that are prefixes of soft keywords is encountered.  Patch by Pablo Galindo.
..
.. date: 2025-06-08-14-24-29
.. gh-issue: 131798
.. nonce: qfw91T
.. section: Core and Builtins
Optimize _CALL_LEN in the JIT when the length is known. Patch by Tomas Roun
..
.. date: 2025-06-06-19-17-22
.. gh-issue: 131798
.. nonce: XoV8Eb
.. section: Core and Builtins
Optimize ``_UNARY_NEGATIVE`` in JIT-compiled code.
..
.. date: 2025-06-06-02-24-42
.. gh-issue: 135148
.. nonce: r-t2sC
.. section: Core and Builtins
Fixed a bug where f-string debug expressions (using =) would incorrectly
strip out parts of strings containing escaped quotes and # characters. Patch
by Pablo Galindo.
..
.. date: 2025-06-06-01-09-44
.. gh-issue: 131798
.. nonce: 1SuxO9
.. section: Core and Builtins
Optimize ``_UNARY_INVERT`` in JIT-compiled code.
..
.. date: 2025-06-05-21-58-30
.. gh-issue: 131798
.. nonce: nt5Ab7
.. section: Core and Builtins
Optimize away ``_CALL_TYPE_1`` in the JIT when the return type is known.
Patch by Tomas Roun
..
.. date: 2025-06-03-21-06-22
.. gh-issue: 133136
.. nonce: Usnvri
.. section: Core and Builtins
Limit excess memory usage in the :term:`free threading` build when a large
dictionary or list is resized and accessed by multiple threads.
..
.. date: 2025-06-02-20-13-37
.. gh-issue: 131798
.. nonce: JQRFvR
.. section: Core and Builtins
Optimize ``_CHECK_METHOD_VERSION`` into ``_CHECK_FUNCTION_VERSION_INLINE``
in JIT-compiled code.
..
.. date: 2025-06-02-13-57-40
.. gh-issue: 116738
.. nonce: ycJsL8
.. section: Library
Make methods in :mod:`heapq` thread-safe on the :term:`free threaded <free
threading>` build.
..
.. date: 2025-05-31-19-24-54
.. gh-issue: 134280
.. nonce: NDVbzY
.. section: Core and Builtins
Disable constant folding for ``~`` with a boolean argument. This moves the
deprecation warning from compile time to runtime.
..
.. date: 2025-05-31-10-26-46
.. gh-issue: 134876
.. nonce: 8mBGJI
.. section: Core and Builtins
Add support to :pep:`768` remote debugging for Linux kernels which don't
have CONFIG_CROSS_MEMORY_ATTACH configured.
..
.. date: 2025-05-30-18-09-54
.. gh-issue: 134889
.. nonce: Ic9UM-
.. section: Core and Builtins
Fix handling of a few opcodes that leave operands on the stack when
optimizing ``LOAD_FAST``.
..
.. date: 2025-05-30-15-56-19
.. gh-issue: 134908
.. nonce: 3a7PxM
.. section: Library
Fix crash when iterating over lines in a text file on the :term:`free
threaded <free threading>` build.
..
.. date: 2025-05-28-23-58-50
.. gh-issue: 117852
.. nonce: BO9g7z
.. section: Core and Builtins
Fix argument checking of :meth:`~agen.athrow`.
..
.. date: 2025-05-27-20-29-00
.. gh-issue: 132617
.. nonce: EmUfQQ
.. section: Core and Builtins
Fix :meth:`dict.update` modification check that could incorrectly raise a
"dict mutated during update" error when a different dictionary was modified
that happens to share the same underlying keys object.
..
.. date: 2025-05-27-20-21-34
.. gh-issue: 131798
.. nonce: b32zkl
.. section: Core and Builtins
Allow the JIT to remove unnecessary ``_ITER_CHECK_TUPLE`` ops.
..
.. date: 2025-05-27-18-59-54
.. gh-issue: 134679
.. nonce: FWPBu6
.. section: Core and Builtins
Fix crash in the :term:`free threading` build's QSBR code that could occur
when changing an object's ``__dict__`` attribute.
..
.. date: 2025-05-26-15-55-50
.. gh-issue: 133912
.. nonce: -xAguL
.. section: Core and Builtins
Fix the C API function ``PyObject_GenericSetDict`` to handle extension
classes with inline values.
..
.. date: 2025-05-25-19-32-15
.. gh-issue: 131798
.. nonce: f5h8aI
.. section: Core and Builtins
Make the JIT optimizer understand that slicing a string/list/tuple returns
the same type.
..
.. date: 2025-05-23-14-54-07
.. gh-issue: 134584
.. nonce: y-WDjf
.. section: Core and Builtins
Add a reference count elimination pass to the JIT compiler. Patch by Ken
Jin.
..
.. date: 2025-05-22-17-49-39
.. gh-issue: 131798
.. nonce: U6ZmFm
.. section: Core and Builtins
Optimize ``_POP_CALL_TWO_LOAD_CONST_INLINE_BORROW``.
..
.. date: 2025-05-22-14-48-19
.. gh-issue: 134381
.. nonce: 2BXhth
.. section: Library
Fix :exc:`RuntimeError` when using a not-started :class:`threading.Thread`
after calling :func:`os.fork`
..
.. date: 2025-05-21-18-02-56
.. gh-issue: 127960
.. nonce: W3J_2X
.. section: Core and Builtins
PyREPL interactive shell no longer starts with ``__package__`` and
``__file__`` global names set to ``_pyrepl`` package internals. Contributed
by Yuichiro Tachibana.
..
.. date: 2025-05-21-15-14-32
.. gh-issue: 130397
.. nonce: aG6EON
.. section: Core and Builtins
Remove special-casing for C stack depth limits for WASI. Due to
WebAssembly's built-in stack protection this does not pose a security
concern.
..
.. date: 2025-05-21-13-57-26
.. gh-issue: 131798
.. nonce: QwS5Bb
.. section: Core and Builtins
JIT: replace ``_LOAD_SMALL_INT`` with ``_LOAD_CONST_INLINE_BORROW``
..
.. date: 2025-05-20-23-32-11
.. gh-issue: 131798
.. nonce: G9ZQZw
.. section: Core and Builtins
Improve the JIT's ability to optimize away cached class attribute and method
loads.
..
.. date: 2025-05-20-14-41-50
.. gh-issue: 128066
.. nonce: qzzGfv
.. section: Core and Builtins
Fixes an edge case where PyREPL improperly threw an error when Python is
invoked on a read only filesystem while trying to write history file
entries.
..
.. date: 2025-05-20-13-58-18
.. gh-issue: 131798
.. nonce: hG8xBw
.. section: Core and Builtins
Improve the JIT's ability to narrow unknown classes to constant values.
..
.. date: 2025-05-19-20-52-53
.. gh-issue: 134268
.. nonce: HPKX1e
.. section: Core and Builtins
Add ``_POP_CALL_TWO_LOAD_CONST_INLINE_BORROW`` and use it to further
optimize ``CALL_ISINSTANCE``.
..
.. date: 2025-05-19-15-15-58
.. gh-issue: 131798
.. nonce: PCP71j
.. section: Core and Builtins
Split ``CALL_LIST_APPEND`` into several uops. Patch by Diego Russo.
..
.. date: 2025-05-18-14-33-23
.. gh-issue: 69605
.. nonce: ZMO49F
.. section: Core and Builtins
When auto-completing an import in the :term:`REPL`, finding no candidates
now issues no suggestion, rather than suggestions from the current
namespace.
..
.. date: 2025-05-18-10-50-46
.. gh-issue: 134170
.. nonce: J0Hvmi
.. section: Core and Builtins
Add colorization to :func:`sys.unraisablehook` by default.
..
.. date: 2025-05-17-20-56-05
.. gh-issue: 91153
.. nonce: afgtG2
.. section: Core and Builtins
Fix a crash when a :class:`bytearray` is concurrently mutated during item
assignment.
..
.. date: 2025-05-17-20-44-51
.. gh-issue: 134158
.. nonce: ewLNLp
.. section: Core and Builtins
Fix coloring of double braces in f-strings and t-strings in the
:term:`REPL`.
..
.. date: 2025-05-16-20-59-12
.. gh-issue: 134119
.. nonce: w8expI
.. section: Core and Builtins
Fix crash when calling :func:`next` on an exhausted template string
iterator. Patch by Jelle Zijlstra.
..
.. date: 2025-05-16-17-25-52
.. gh-issue: 134100
.. nonce: 5-FbLK
.. section: Core and Builtins
Fix a use-after-free bug that occurs when an imported module isn't in
:data:`sys.modules` after its initial import. Patch by Nico-Posada.
..
.. date: 2025-05-16-09-06-38
.. gh-issue: 134036
.. nonce: st2e-B
.. section: Core and Builtins
Improve :exc:`SyntaxError` message when using invalid :keyword:`raise`
statements.
..
.. date: 2025-05-15-11-38-16
.. gh-issue: 133999
.. nonce: uBZ8uS
.. section: Core and Builtins
Fix :exc:`SyntaxError` regression in :keyword:`except` parsing after
:gh:`123440`.
..
.. date: 2025-05-11-13-40-42
.. gh-issue: 133886
.. nonce: ryBAyo
.. section: Core and Builtins
Fix :func:`sys.remote_exec` for non-ASCII paths in non-UTF-8 locales and
non-UTF-8 paths in UTF-8 locales.
..
.. date: 2025-05-11-09-40-19
.. gh-issue: 133400
.. nonce: zkWla8
.. section: Core and Builtins
Fixed Ctrl+D (^D) behavior in _pyrepl module to match old pre-3.13 REPL
behavior.
..
.. date: 2025-05-10-17-12-27
.. gh-issue: 133703
.. nonce: bVM-re
.. section: Core and Builtins
Fix hashtable in dict can be bigger than intended in some situations.
..
.. date: 2025-05-09-18-11-21
.. gh-issue: 133778
.. nonce: pWEV3t
.. section: Core and Builtins
Fix bug where assigning to the :attr:`~type.__annotations__` attributes of
classes defined under ``from __future__ import annotations`` had no effect.
..
.. date: 2025-05-08-22-19-10
.. gh-issue: 133711
.. nonce: e91wUy
.. section: Core and Builtins
Implement :pep:`686`: Enable :ref:`Python UTF-8 Mode <utf8-mode>` by
default. Patch by Adam Turner.
..
.. date: 2025-05-08-13-48-02
.. gh-issue: 132762
.. nonce: tKbygC
.. section: Core and Builtins
:meth:`~dict.fromkeys` no longer loops forever when adding a small set of
keys to a large base dict. Patch by Angela Liss.
..
.. date: 2025-05-07-23-26-53
.. gh-issue: 133541
.. nonce: bHIC55
.. section: Core and Builtins
Inconsistent indentation in user input crashed the new REPL when syntax
highlighting was active. This is now fixed.
..
.. date: 2025-05-06-15-01-41
.. gh-issue: 133516
.. nonce: RqWVf2
.. section: Core and Builtins
Raise :exc:`ValueError` when constants ``True``, ``False`` or ``None`` are
used as an identifier after NFKC normalization.
..
.. date: 2025-05-03-22-31-53
.. gh-issue: 131798
.. nonce: fQ0ato
.. section: Core and Builtins
Allow the JIT to remove int guards after ``_GET_LEN`` by setting the return
type to int.
..
.. date: 2025-05-03-13-36-01
.. gh-issue: 131798
.. nonce: U4_QEJ
.. section: Core and Builtins
Split ``CALL_ISINSTANCE`` into several uops, allowing the JIT to remove some
of them.
..
.. date: 2025-04-30-14-13-01
.. gh-issue: 132554
.. nonce: GqQaUp
.. section: Core and Builtins
Change iteration to use "virtual iterators" for sequences. Instead of
creating an iterator, a tagged integer representing the next index is pushed
to the stack above the iterable. For non-sequence iterators, ``NULL`` is
pushed.
..
.. date: 2025-04-28-18-59-11
.. gh-issue: 130821
.. nonce: B11LU1
.. section: Core and Builtins
Enhance wrong type error messages and make them more consistent. Patch by
Semyon Moroz.
..
.. date: 2025-04-26-17-50-01
.. gh-issue: 131798
.. nonce: XiOgw5
.. section: Core and Builtins
Narrow the return type and constant-evaluate ``CALL_ISINSTANCE`` for a
subset of known values in the JIT. Patch by Tomas Roun
..
.. date: 2025-04-19-17-16-46
.. gh-issue: 132542
.. nonce: 7T_TY_
.. section: Core and Builtins
Update :attr:`Thread.native_id <threading.Thread.native_id>` after
:manpage:`fork(2)` to ensure accuracy. Patch by Noam Cohen.
..
.. date: 2025-04-19-16-22-47
.. gh-issue: 132732
.. nonce: jgqhlF
.. section: Library
Automatically constant evaluate bytecode operations marked as pure in the
JIT optimizer.
..
.. date: 2025-04-16-12-01-13
.. gh-issue: 127971
.. nonce: pMDOQ0
.. section: Core and Builtins
Fix off-by-one read beyond the end of a string in string search.
..
.. date: 2025-04-10-01-52-42
.. gh-issue: 132042
.. nonce: fePwlj
.. section: Core and Builtins
Improve class creation times by up to 12% by pre-computing type slots just
once. Patch by Sergey Miryanov.
..
.. date: 2025-04-04-16-41-00
.. gh-issue: 133379
.. nonce: asdjhjdf
.. section: Core and Builtins
Correct usage of *arguments* in error messages.
..
.. date: 2025-03-14-13-08-20
.. gh-issue: 127266
.. nonce: _tyfBp
.. section: Core and Builtins
In the free-threaded build, avoid data races caused by updating type slots
or type flags after the type was initially created.  For those (typically
rare) cases, use the stop-the-world mechanism.  Remove the use of atomics
when reading or writing type flags.  The use of atomics is not sufficient to
avoid races (since flags are sometimes read without a lock and without
atomics) and are no longer required.
..
.. date: 2025-02-22-01-23-23
.. gh-issue: 130425
.. nonce: x5SNQ8
.. section: Core and Builtins
Add ``"Did you mean: 'attr'?"`` suggestion when using ``del obj.attr`` if
``attr`` does not exist.
..
.. date: 2025-01-08-12-52-47
.. gh-issue: 128640
.. nonce: 9nbh9z
.. section: Core and Builtins
Fix a crash when using threads inside of a subinterpreter.
..
.. date: 2024-06-04-20-26-21
.. gh-issue: 116738
.. nonce: q_hPYq
.. section: Library
Make the module :mod:`json` safe to use under the free-threading build.
..
.. date: 2024-05-24-07-02-47
.. gh-issue: 119494
.. nonce: x3KUMC
.. section: Core and Builtins
Exception text when trying to delete attributes of types was clarified.
..
.. date: 2025-10-10-20-59-07
.. gh-issue: 139924
.. nonce: ALByCb
.. section: C API
Function watchers can now receive a PyFunction_PYFUNC_EVENT_MODIFY_QUALNAME
event when a watched functions qualname is changed.
..
.. date: 2025-10-07-12-51-32
.. gh-issue: 111489
.. nonce: LCKKlg
.. section: C API
Add :c:func:`PyTuple_FromArray` to create a :class:`tuple` from an array.
Patch by Victor Stinner.
..
.. date: 2025-09-14-14-44-24
.. gh-issue: 136355
.. nonce: LCaYyC
.. section: C API
Deprecate :c:member:`PyConfig.bytes_warning` field and schedule its removal
in 3.17.
..
.. date: 2025-09-14-13-09-47
.. gh-issue: 138886
.. nonce: dlcTXL
.. section: C API
Remove deprecated :c:func:`!PySys_ResetWarnOptions` C-API function.
..
.. date: 2025-09-12-13-05-20
.. gh-issue: 129813
.. nonce: dJZpME
.. section: C API
Implement :pep:`782`, the :c:type:`PyBytesWriter` API. Add functions:
* :c:func:`PyBytesWriter_Create`
* :c:func:`PyBytesWriter_Discard`
* :c:func:`PyBytesWriter_FinishWithPointer`
* :c:func:`PyBytesWriter_FinishWithSize`
* :c:func:`PyBytesWriter_Finish`
* :c:func:`PyBytesWriter_Format`
* :c:func:`PyBytesWriter_GetData`
* :c:func:`PyBytesWriter_GetSize`
* :c:func:`PyBytesWriter_GrowAndUpdatePointer`
* :c:func:`PyBytesWriter_Grow`
* :c:func:`PyBytesWriter_Resize`
* :c:func:`PyBytesWriter_WriteBytes`
Patch by Victor Stinner.
..
.. date: 2025-08-19-15-31-36
.. gh-issue: 137956
.. nonce: P4TK1d
.. section: C API
Display and raise an exception if an extension compiled for
non-free-threaded Python is loaded in a free-threaded interpreter.
..
.. date: 2025-08-13-13-41-04
.. gh-issue: 137573
.. nonce: r6uwRf
.. section: C API
Mark ``_PyOptimizer_Optimize`` as :c:macro:`Py_NO_INLINE` to prevent stack
overflow crashes on macOS.
..
.. date: 2025-07-31-04-30-42
.. gh-issue: 128813
.. nonce: opL-Pv
.. section: C API
Functions :c:func:`_Py_c_sum`, :c:func:`_Py_c_diff`, :c:func:`_Py_c_neg`,
:c:func:`_Py_c_prod`, :c:func:`_Py_c_quot`, :c:func:`_Py_c_pow` and
previously undocumented :c:func:`_Py_c_abs` are :term:`soft deprecated`.
Deprecate also :c:member:`~PyComplexObject.cval` field of the
:c:type:`PyComplexObject` type. Patch by Sergey B Kirpichev.
..
.. date: 2025-07-29-18-00-22
.. gh-issue: 137210
.. nonce: DD4VEm
.. section: C API
Add API for checking an extension module's ABI compatibility:
:c:data:`Py_mod_abi`, :c:func:`PyABIInfo_Check`, :c:macro:`PyABIInfo_VAR`
and :c:data:`Py_mod_abi`.
..
.. date: 2025-07-23-22-30-23
.. gh-issue: 136759
.. nonce: ffB4wO
.. section: C API
Rename ``lock.h`` to ``pylock.h`` to avoid potential include conflicts.
..
.. date: 2025-07-22-15-18-08
.. gh-issue: 112068
.. nonce: 4WvT-8
.. section: C API
Revert support of nullable arguments in :c:func:`PyArg_Parse`.
..
.. date: 2025-07-08-22-07-54
.. gh-issue: 136006
.. nonce: XRU5w4
.. section: C API
On Solaris, the :c:macro:`!Py_NAN` macro now expands to a :c:type:`!double`
instead of a function address. Patch by Bénédikt Tran.
..
.. date: 2025-07-01-16-22-39
.. gh-issue: 135075
.. nonce: angu3J
.. section: C API
Make :c:func:`PyObject_SetAttr` and :c:func:`PyObject_SetAttrString` fail if
called with ``NULL`` value and an exception set. Patch by Victor Stinner.
..
.. date: 2025-06-25-01-03-10
.. gh-issue: 135906
.. nonce: UBrCWq
.. section: C API
Fix compilation errors when compiling the internal headers with a C++
compiler.
..
.. date: 2025-06-24-11-10-01
.. gh-issue: 133296
.. nonce: lIEuVJ
.. section: C API
New variants for the critical section API that accept one or two
:c:type:`PyMutex` pointers rather than :c:type:`PyObject` instances are now
public in the non-limited C API.
..
.. date: 2025-06-19-12-47-18
.. gh-issue: 133157
.. nonce: 1WA85f
.. section: C API
Remove the private, undocumented macro
:c:macro:`!_Py_NO_SANITIZE_UNDEFINED`.
..
.. date: 2025-06-05-11-06-07
.. gh-issue: 134989
.. nonce: 74p4ud
.. section: C API
Fix ``Py_RETURN_NONE``, ``Py_RETURN_TRUE`` and ``Py_RETURN_FALSE`` macros in
the limited C API 3.11 and older: don't treat ``Py_None``, ``Py_True`` and
``Py_False`` as immortal. Patch by Victor Stinner.
..
.. date: 2025-06-02-13-19-22
.. gh-issue: 134989
.. nonce: sDDyBN
.. section: C API
Implement :c:func:`PyObject_DelAttr` and :c:func:`PyObject_DelAttrString` as
macros in the limited C API 3.12 and older. Patch by Victor Stinner.
..
.. date: 2025-05-30-11-33-17
.. gh-issue: 134745
.. nonce: GN-zk2
.. section: C API
Change :c:func:`!PyThread_allocate_lock` implementation to ``PyMutex``. On
Windows, :c:func:`!PyThread_acquire_lock_timed` now supports the *intr_flag*
parameter: it can be interrupted. Patch by Victor Stinner.
..
.. date: 2025-05-29-16-56-23
.. gh-issue: 134891
.. nonce: 7eKO8U
.. section: C API
Add :c:type:`PyUnstable_Unicode_GET_CACHED_HASH` to get the cached hash of a
string.
..
.. date: 2025-05-20-17-13-51
.. gh-issue: 134009
.. nonce: CpCmry
.. section: C API
Expose :c:func:`PyMutex_IsLocked` as part of the public C API.
..
.. date: 2025-05-17-14-41-21
.. gh-issue: 134144
.. nonce: xVpZik
.. section: C API
Fix crash when calling :c:func:`Py_EndInterpreter` with a :term:`thread
state` that isn't the initial thread for the interpreter.
..
.. date: 2025-05-13-16-06-46
.. gh-issue: 133968
.. nonce: 6alWst
.. section: C API
Add :c:func:`PyUnicodeWriter_WriteASCII` function to write an ASCII string
into a :c:type:`PyUnicodeWriter`. The function is faster than
:c:func:`PyUnicodeWriter_WriteUTF8`, but has an undefined behavior if the
input string contains non-ASCII characters. Patch by Victor Stinner.
..
.. date: 2025-05-08-13-14-45
.. gh-issue: 133644
.. nonce: J8_KZ2
.. section: C API
Remove deprecated Python initialization getter functions ``Py_Get*``. Patch
by Bénédikt Tran.
..
.. date: 2025-05-08-12-40-59
.. gh-issue: 133644
.. nonce: FNexLJ
.. section: C API
Remove deprecated function :c:func:`!PyWeakref_GetObject` and macro
:c:macro:`!PyWeakref_GET_OBJECT`. Use :c:func:`PyWeakref_GetRef` instead.
Patch by Bénédikt Tran.
..
.. date: 2025-05-08-12-25-47
.. gh-issue: 133644
.. nonce: Yb86Rm
.. section: C API
Remove deprecated alias :c:func:`!PyImport_ImportModuleNoBlock` of
:c:func:`PyImport_ImportModule`. Patch by Bénédikt Tran.
..
.. date: 2025-05-07-21-18-00
.. gh-issue: 133610
.. nonce: asdfjs
.. section: C API
Remove deprecated functions :c:func:`!PyUnicode_AsDecodedObject`,
:c:func:`!PyUnicode_AsDecodedUnicode`, :c:func:`!PyUnicode_AsEncodedObject`,
and :c:func:`!PyUnicode_AsEncodedUnicode`.
..
.. date: 2025-04-17-12-37-27
.. gh-issue: 132629
.. nonce: 01ArwX
.. section: C API
For unsigned integer formats in :c:func:`PyArg_ParseTuple`, accepting Python
integers with value that is larger than the maximal value for the C type or
less than the minimal value for the corresponding signed integer type of the
same size is now deprecated.
..
.. date: 2025-04-14-07-41-28
.. gh-issue: 131185
.. nonce: ZCjMHD
.. section: C API
:c:func:`PyGILState_Ensure` no longer crashes when called after interpreter
finalization.
..
.. date: 2023-10-18-14-36-35
.. gh-issue: 108512
.. nonce: fMZLfr
.. section: C API
Add functions :c:func:`PySys_GetAttr`, :c:func:`PySys_GetAttrString`,
:c:func:`PySys_GetOptionalAttr` and :c:func:`PySys_GetOptionalAttrString`.
..
.. date: 2025-09-24-13-59-26
.. gh-issue: 138489
.. nonce: 1AcuZM
.. section: Build
When cross-compiling for WASI by ``build_wasm`` or ``build_emscripten``, the
``build-details.json`` step is now included in the build process, just like
with native builds.
This fixes the ``libinstall`` task which requires the ``build-details.json``
file during the process.
..
.. date: 2025-09-04-12-16-31
.. gh-issue: 138497
.. nonce: Y_5YXh
.. section: Build
The LLVM version used by the JIT at build time can now be modified using the
``LLVM_VERSION`` environment variable. Use this at your own risk, as there
is only one officially supported LLVM version. For more information, please
check ``Tools/jit/README.md``.
..
.. date: 2025-08-27-11-32-02
.. gh-issue: 95952
.. nonce: KSymc7
.. section: Build
When cross-compiling for WASI, require that the HOSTRUNNER environment
variable be explicitly set.
This was needed as macOS lacks the appropriate CLI tools to set a reasonable
default.
..
.. date: 2025-08-27-09-52-45
.. gh-issue: 138061
.. nonce: fMVS9w
.. section: Build
Ensure reproducible builds by making JIT stencil header generation
deterministic.
..
.. date: 2025-08-26-21-18-32
.. gh-issue: 128042
.. nonce: 5voC8H
.. section: Build
``./configure`` now warns when ``--enable-optimizations`` and ``CFLAGS=-O0``
are both set, suggesting removing ``-O0`` from ``CFLAGS`` for optimal
performance.  Patch by Taegyun Kim.
..
.. date: 2025-08-13-12-10-12
.. gh-issue: 132339
.. nonce: 3Czz5y
.. section: Build
Add support for OpenSSL 3.5.
..
.. date: 2025-07-18-17-15-00
.. gh-issue: 135621
.. nonce: 9cyCNb
.. section: Build
PyREPL no longer depends on the :mod:`curses` standard library. Contributed
by Łukasz Langa.
..
.. date: 2025-06-25-13-27-14
.. gh-issue: 135927
.. nonce: iCNPQc
.. section: Build
Fix building with MSVC when passing option ``/std:clatest``.
..
.. date: 2025-06-16-07-20-28
.. gh-issue: 119132
.. nonce: fcI8s7
.. section: Build
Remove "experimental" tag from the CPython free-threading build.
..
.. date: 2025-06-14-10-32-11
.. gh-issue: 135497
.. nonce: ajlV4F
.. section: Build
Fix the detection of ``MAXLOGNAME`` in the ``configure.ac`` script.
..
.. date: 2025-05-30-11-02-30
.. gh-issue: 134923
.. nonce: gBkRg4
.. section: Build
Windows builds with profile-guided optimization enabled now use
``/GENPROFILE`` and ``/USEPROFILE`` instead of deprecated ``/LTCG:``
options.
..
.. date: 2025-05-24-16-59-20
.. gh-issue: 134632
.. nonce: i0W2hc
.. section: Build
Fixed ``build-details.json`` generation to use ``INCLUDEPY``, in order to
reference the ``pythonX.Y`` subdirectory of the include directory, as
required in :pep:`739`, instead of the top-level include directory.
..
.. date: 2025-05-21-22-13-30
.. gh-issue: 134486
.. nonce: yvdL6f
.. section: Build
The :mod:`ctypes` module now performs a more portable test for the
definition of :manpage:`alloca(3)`, fixing a compilation failure on NetBSD.
..
.. date: 2025-05-21-19-46-28
.. gh-issue: 134455
.. nonce: vdwlrq
.. section: Build
Fixed ``build-details.json`` generation to use the correct ``c_api.headers``
as defined in :pep:`739`, instead of ``c_api.include``.
..
.. date: 2025-05-19-18-09-20
.. gh-issue: 134273
.. nonce: ZAliyy
.. section: Build
Add support for configuring compiler flags for the JIT with ``CFLAGS_JIT``
..
.. date: 2025-05-16-07-46-06
.. gh-issue: 115119
.. nonce: ALBgS_
.. section: Build
Removed implicit fallback to the bundled copy of the ``libmpdec`` library.
Now this should be explicitly enabled via :option:`--with-system-libmpdec`
set to ``no`` or :option:`!--without-system-libmpdec`.  Patch by Sergey B
Kirpichev.
..
.. date: 2025-05-14-09-43-48
.. gh-issue: 131769
.. nonce: H0oy5x
.. section: Build
Fix detecting when the build Python in a cross-build is a pydebug build.
..
.. date: 2025-04-16-09-38-48
.. gh-issue: 117088
.. nonce: EFt_5c
.. section: Build
AIX linker don't support -h option, so avoid it through platform check
..
.. date: 2025-01-03-13-02-06
.. gh-issue: 123681
.. nonce: gQ67nK
.. section: Build
Check the ``strftime()`` behavior at runtime instead of at the compile time
to support cross-compiling. Remove the internal macro
``_Py_NORMALIZE_CENTURY``.
..
.. date: 2024-12-04-10-00-35
.. gh-issue: 127545
.. nonce: t0THjE
.. section: Build
Fix crash when building on Linux/m68k.

.. bpo: 38576
.. date: 2020-03-14-14-57-44
.. nonce: OowwQn
.. release date: 2020-03-23
.. section: Security
Disallow control characters in hostnames in http.client, addressing
:cve:`2019-18348`. Such potentially malicious header injection URLs now cause a
InvalidURL to be raised.
..
.. bpo: 40010
.. date: 2020-03-20-13-51-55
.. nonce: QGf5s8
.. section: Core and Builtins
Optimize pending calls in multithreaded applications. If a thread different
than the main thread schedules a pending call (:c:func:`Py_AddPendingCall`),
the bytecode evaluation loop is no longer interrupted at each bytecode
instruction to check for pending calls which cannot be executed. Only the
main thread can execute pending calls.
Previously, the bytecode evaluation loop was interrupted at each instruction
until the main thread executes pending calls.
..
.. bpo: 1635741
.. date: 2020-03-20-13-42-35
.. nonce: bhIu5M
.. section: Core and Builtins
Port _weakref extension module to multiphase initialization (:pep:`489`).
..
.. bpo: 1635741
.. date: 2020-03-19-23-34-22
.. nonce: ayunLM
.. section: Core and Builtins
Port _collections module to multiphase initialization (:pep:`489`).
..
.. bpo: 40010
.. date: 2020-03-19-02-26-13
.. nonce: Y-LIR0
.. section: Core and Builtins
Optimize signal handling in multithreaded applications. If a thread
different than the main thread gets a signal, the bytecode evaluation loop
is no longer interrupted at each bytecode instruction to check for pending
signals which cannot be handled. Only the main thread of the main
interpreter can handle signals.
Previously, the bytecode evaluation loop was interrupted at each instruction
until the main thread handles signals.
..
.. bpo: 39984
.. date: 2020-03-19-00-45-37
.. nonce: u-bHIq
.. section: Core and Builtins
If :c:func:`Py_AddPendingCall` is called in a subinterpreter, the function
is now scheduled to be called from the subinterpreter, rather than being
called from the main interpreter. Each subinterpreter now has its own list
of scheduled calls.
..
.. bpo: 1635741
.. date: 2020-03-18-19-48-53
.. nonce: ELEihr
.. section: Core and Builtins
Port _heapq module to multiphase initialization.
..
.. bpo: 1635741
.. date: 2020-03-18-00-17-26
.. nonce: 7AtdhP
.. section: Core and Builtins
Port itertools module to multiphase initialization (:pep:`489`).
..
.. bpo: 37207
.. date: 2020-03-17-22-35-29
.. nonce: sBAV1j
.. section: Core and Builtins
Speed up calls to ``frozenset()`` by using the :pep:`590` ``vectorcall``
calling convention. Patch by Donghee Na.
..
.. bpo: 39984
.. date: 2020-03-17-01-55-33
.. nonce: y5Chgb
.. section: Core and Builtins
subinterpreters: Move ``_PyRuntimeState.ceval.tracing_possible`` to
``PyInterpreterState.ceval.tracing_possible``: each interpreter now has its
own variable.
..
.. bpo: 37207
.. date: 2020-03-15-23-16-00
.. nonce: 6XbnQA
.. section: Core and Builtins
Speed up calls to ``set()`` by using the :pep:`590` ``vectorcall`` calling
convention. Patch by Donghee Na.
..
.. bpo: 1635741
.. date: 2020-03-15-20-51-15
.. nonce: iH0JND
.. section: Core and Builtins
Port _statistics module to multiphase initialization (:pep:`489`).
..
.. bpo: 39968
.. date: 2020-03-15-13-51-10
.. nonce: f-Xi39
.. section: Core and Builtins
Use inline function to replace extension modules' get_module_state macros.
..
.. bpo: 39965
.. date: 2020-03-15-03-52-01
.. nonce: Od3ZdP
.. section: Core and Builtins
Correctly raise ``SyntaxError`` if *await* is used inside non-async
functions and ``PyCF_ALLOW_TOP_LEVEL_AWAIT`` is set (like in the asyncio
REPL). Patch by Pablo Galindo.
..
.. bpo: 39562
.. date: 2020-03-12-22-13-50
.. nonce: E2u273
.. section: Core and Builtins
Allow executing asynchronous comprehensions on the top level when the
``PyCF_ALLOW_TOP_LEVEL_AWAIT`` flag is given. Patch by Batuhan Taskaya.
..
.. bpo: 37207
.. date: 2020-03-12-02-41-12
.. nonce: ye7OM3
.. section: Core and Builtins
Speed up calls to ``tuple()`` by using the :pep:`590` ``vectorcall`` calling
convention. Patch by Donghee Na.
..
.. bpo: 38373
.. date: 2020-03-11-12-28-16
.. nonce: FE9S21
.. section: Core and Builtins
Changed list overallocation strategy. It no longer overallocates if the new
size is closer to overallocated size than to the old size and adds padding.
..
.. bpo: 39926
.. date: 2020-03-10-19-14-42
.. nonce: H19bAa
.. section: Core and Builtins
Update Unicode database to Unicode version 13.0.0.
..
.. bpo: 19466
.. date: 2020-03-08-12-11-38
.. nonce: OdOpXP
.. section: Core and Builtins
Clear the frames of daemon threads earlier during the Python shutdown to
call objects destructors. So "unclosed file" resource warnings are now
emitted for daemon threads in a more reliable way.
..
.. bpo: 38894
.. date: 2020-03-06-21-04-39
.. nonce: nfcGKv
.. section: Core and Builtins
Fix a bug that was causing incomplete results when calling
``pathlib.Path.glob`` in the presence of symlinks that point to files where
the user does not have read access. Patch by Pablo Galindo and Matt
Wozniski.
..
.. bpo: 39877
.. date: 2020-03-06-18-30-00
.. nonce: bzd1y0
.. section: Core and Builtins
Fix :c:func:`PyEval_RestoreThread` random crash at exit with daemon threads.
It now accesses the ``_PyRuntime`` variable directly instead of using
``tstate->interp->runtime``, since ``tstate`` can be a dangling pointer
after :c:func:`Py_Finalize` has been called. Moreover, the daemon thread now
exits before trying to take the GIL.
..
.. bpo: 39871
.. date: 2020-03-06-06-12-37
.. nonce: dCAj_2
.. section: Core and Builtins
Fix a possible :exc:`SystemError` in ``math.{atan2,copysign,remainder}()``
when the first argument cannot be converted to a :class:`float`. Patch by
Zackery Spytz.
..
.. bpo: 39776
.. date: 2020-03-02-20-12-33
.. nonce: fNaxi_
.. section: Core and Builtins
Fix race condition where threads created by PyGILState_Ensure() could get a
duplicate id.
This affects consumers of tstate->id like the contextvar caching machinery,
which could return invalid cached objects under heavy thread load (observed
in embedded scenarios).
..
.. bpo: 39778
.. date: 2020-03-02-19-21-21
.. nonce: _YGLEc
.. section: Core and Builtins
Fixed a crash due to incorrect handling of weak references in
``collections.OrderedDict`` classes. Patch by Pablo Galindo.
..
.. bpo: 1635741
.. date: 2020-02-22-14-33-59
.. nonce: BTJ0cX
.. section: Core and Builtins
Port audioop extension module to multiphase initialization (:pep:`489`).
..
.. bpo: 39702
.. date: 2020-02-20-08-12-52
.. nonce: 4_AmyF
.. section: Core and Builtins
Relax :term:`decorator` grammar restrictions to allow any valid expression
(:pep:`614`).
..
.. bpo: 38091
.. date: 2020-02-14-23-10-07
.. nonce: pwR0K7
.. section: Core and Builtins
Tweak import deadlock detection code to not deadlock itself.
..
.. bpo: 1635741
.. date: 2020-02-05-07-55-57
.. nonce: H_tCC9
.. section: Core and Builtins
Port _locale extension module to multiphase initialization (:pep:`489`).
..
.. bpo: 39087
.. date: 2020-02-03-21-12-39
.. nonce: YnbUpL
.. section: Core and Builtins
Optimize :c:func:`PyUnicode_AsUTF8` and :c:func:`PyUnicode_AsUTF8AndSize`
slightly when they need to create internal UTF-8 cache.
..
.. bpo: 39520
.. date: 2020-02-02-00-12-07
.. nonce: uicBq6
.. section: Core and Builtins
Fix unparsing of ext slices with no items (``foo[:,]``). Patch by Batuhan
Taskaya.
..
.. bpo: 39220
.. date: 2020-01-06-13-58-37
.. nonce: KGFovE
.. section: Core and Builtins
Do not optimize annotations if 'from __future__ import annotations' is used.
Patch by Pablo Galindo.
..
.. bpo: 35712
.. date: 2019-05-08-11-11-45
.. nonce: KJthus
.. section: Core and Builtins
Using :data:`NotImplemented` in a boolean context has been deprecated. Patch
contributed by Josh Rosenberg.
..
.. bpo: 22490
.. date: 2018-09-23-16-32-58
.. nonce: 8e0YDf
.. section: Core and Builtins
Don't leak environment variable ``__PYVENV_LAUNCHER__`` into the interpreter
session on macOS.
..
.. bpo: 39830
.. date: 2020-03-23-05-21-13
.. nonce: IkqU1Y
.. section: Library
Add :class:`zipfile.Path` to ``__all__`` in the :mod:`zipfile` module.
..
.. bpo: 40000
.. date: 2020-03-18-12-54-25
.. nonce: FnsPZC
.. section: Library
Improved error messages for validation of ``ast.Constant`` nodes. Patch by
Batuhan Taskaya.
..
.. bpo: 39999
.. date: 2020-03-18-11-50-25
.. nonce: 8aOXDT
.. section: Library
``__module__`` of the AST node classes is now set to "ast" instead of
"_ast". Added docstrings for dummy AST node classes and deprecated
attributes.
..
.. bpo: 39991
.. date: 2020-03-17-12-40-38
.. nonce: hLPPs4
.. section: Library
:func:`uuid.getnode` now skips IPv6 addresses with the same string length
than a MAC address (17 characters): only use MAC addresses.
..
.. bpo: 39988
.. date: 2020-03-17-09-35-00
.. nonce: kXGl35
.. section: Library
Deprecated ``ast.AugLoad`` and ``ast.AugStore`` node classes because they
are no longer used.
..
.. bpo: 39656
.. date: 2020-03-16-11-38-45
.. nonce: MaNOgm
.. section: Library
Ensure ``bin/python3.#`` is always present in virtual environments on POSIX
platforms - by Anthony Sottile.
..
.. bpo: 39969
.. date: 2020-03-15-17-56-48
.. nonce: 6snm0c
.. section: Library
Deprecated ``ast.Param`` node class because it's no longer used. Patch by
Batuhan Taskaya.
..
.. bpo: 39360
.. date: 2020-03-15-05-41-05
.. nonce: cmcU5p
.. section: Library
Ensure all workers exit when finalizing a :class:`multiprocessing.Pool`
implicitly via the module finalization handlers of multiprocessing. This
fixes a deadlock situation that can be experienced when the Pool is not
properly finalized via the context manager or a call to
``multiprocessing.Pool.terminate``. Patch by Batuhan Taskaya and Pablo
Galindo.
..
.. bpo: 35370
.. date: 2020-03-13-14-41-28
.. nonce: df50Q7
.. section: Library
sys.settrace(), sys.setprofile() and _lsprof.Profiler.enable() now properly
report :c:func:`PySys_Audit` error if "sys.setprofile" or "sys.settrace"
audit event is denied.
..
.. bpo: 39936
.. date: 2020-03-12-21-59-47
.. nonce: Ca9IKe
.. section: Library
AIX: Fix _aix_support module when the subprocess is not available, when
building Python from scratch. It now uses new private _bootsubprocess
module, rather than having two implementations depending if subprocess is
available or not. So _aix_support.aix_platform() result is now the same if
subprocess is available or not.
..
.. bpo: 36144
.. date: 2020-03-12-11-55-16
.. nonce: 9bxGH_
.. section: Library
:class:`collections.OrderedDict` now implements ``|`` and ``|=``
(:pep:`584`).
..
.. bpo: 39652
.. date: 2020-03-11-23-08-25
.. nonce: gbasrk
.. section: Library
The column name found in ``sqlite3.Cursor.description`` is now truncated on
the first '[' only if the PARSE_COLNAMES option is set.
..
.. bpo: 39915
.. date: 2020-03-10-19-38-47
.. nonce: CjPeiY
.. section: Library
Ensure :attr:`unittest.mock.AsyncMock.await_args_list` has call objects in
the order of awaited arguments instead of using
:attr:`unittest.mock.Mock.call_args` which has the last value of the call.
Patch by Karthikeyan Singaravelan.
..
.. bpo: 36144
.. date: 2020-03-10-19-22-31
.. nonce: LABm7W
.. section: Library
Updated :data:`os.environ` and :data:`os.environb` to support :pep:`584`'s
merge (``|``) and update (``|=``) operators.
..
.. bpo: 38662
.. date: 2020-03-10-15-32-31
.. nonce: o1DMXj
.. section: Library
The ``ensurepip`` module now invokes ``pip`` via the ``runpy`` module. Hence
it is no longer tightly coupled with the internal API of the bundled ``pip``
version, allowing easier updates to a newer ``pip`` version both internally
and for distributors.
..
.. bpo: 38075
.. date: 2020-03-10-12-52-06
.. nonce: qbESAF
.. section: Library
Fix the :meth:`random.Random.seed` method when a :class:`bool` is passed as
the seed.
..
.. bpo: 39916
.. date: 2020-03-09-18-56-27
.. nonce: BHHyp3
.. section: Library
More reliable use of ``os.scandir()`` in ``Path.glob()``. It no longer emits
a ResourceWarning when interrupted.
..
.. bpo: 39850
.. date: 2020-03-09-01-45-06
.. nonce: eaJNIE
.. section: Library
:mod:`multiprocessing` now supports abstract socket addresses (if abstract
sockets are supported in the running platform). When creating arbitrary
addresses (like when default-constructing
:class:`multiprocessing.connection.Listener` objects) abstract sockets are
preferred to avoid the case when the temporary-file-generated address is too
large for an AF_UNIX socket address. Patch by Pablo Galindo.
..
.. bpo: 36287
.. date: 2020-03-08-09-53-55
.. nonce: mxr5m8
.. section: Library
:func:`ast.dump` no longer outputs optional fields and attributes with
default values. The default values for optional fields and attributes of AST
nodes are now set as class attributes (e.g. ``Constant.kind`` is set to
``None``).
..
.. bpo: 39889
.. date: 2020-03-07-16-44-51
.. nonce: 3RYqeX
.. section: Library
Fixed :func:`ast.unparse` for extended slices containing a single element
(e.g. ``a[i:j,]``). Remove redundant tuples when index with a tuple (e.g.
``a[i, j]``).
..
.. bpo: 39828
.. date: 2020-03-05-00-57-49
.. nonce: yWq9NJ
.. section: Library
Fix :mod:`json.tool` to catch :exc:`BrokenPipeError`. Patch by Donghee Na.
..
.. bpo: 13487
.. date: 2020-03-04-16-10-59
.. nonce: gqe4Fb
.. section: Library
Avoid a possible *"RuntimeError: dictionary changed size during iteration"*
from :func:`inspect.getmodule` when it tried to loop through
:data:`sys.modules`.
..
.. bpo: 39674
.. date: 2020-03-03-16-21-41
.. nonce: HJVkD5
.. section: Library
Revert "bpo-37330: open() no longer accept 'U' in file mode". The "U" mode
of open() is kept in Python 3.9 to ease transition from Python 2.7, but will
be removed in Python 3.10.
..
.. bpo: 28577
.. date: 2020-03-02-23-52-38
.. nonce: EK91ae
.. section: Library
The hosts method on 32-bit prefix length IPv4Networks and 128-bit prefix
IPv6Networks now returns a list containing the single Address instead of an
empty list.
..
.. bpo: 39826
.. date: 2020-03-02-15-15-01
.. nonce: DglHk7
.. section: Library
Add getConnection method to logging HTTPHandler to enable custom
connections.
..
.. bpo: 39763
.. date: 2020-03-02-14-43-19
.. nonce: 5a822c
.. section: Library
Reimplement ``distutils.spawn.spawn`` function with the
:mod:`subprocess` module.
..
.. bpo: 39794
.. date: 2020-02-29-19-17-39
.. nonce: 7VjatS
.. section: Library
Add --without-decimal-contextvar build option.  This enables a thread-local
rather than a coroutine local context.
..
.. bpo: 36144
.. date: 2020-02-29-15-54-08
.. nonce: 4GgTZs
.. section: Library
:class:`collections.defaultdict` now implements ``|`` (:pep:`584`).
..
.. bpo: 39517
.. date: 2020-02-29-11-20-50
.. nonce: voQZb8
.. section: Library
Fix runpy.run_path() when using pathlike objects
..
.. bpo: 39775
.. date: 2020-02-28-16-42-16
.. nonce: IuSvVb
.. section: Library
Change ``inspect.Signature.parameters`` back to ``collections.OrderedDict``.
This was changed to ``dict`` in Python 3.9.0a4.
..
.. bpo: 39678
.. date: 2020-02-28-12-59-30
.. nonce: 3idfxM
.. section: Library
Refactor queue_manager in :class:`concurrent.futures.ProcessPoolExecutor` to
make it easier to maintain.
..
.. bpo: 39764
.. date: 2020-02-27-18-21-07
.. nonce: wqPk68
.. section: Library
Fix AttributeError when calling get_stack on a PyAsyncGenObject Task
..
.. bpo: 39769
.. date: 2020-02-27-00-40-21
.. nonce: hJmxu4
.. section: Library
The :func:`compileall.compile_dir` function's *ddir* parameter and the
compileall command line flag ``-d`` no longer write the wrong pathname to the
generated pyc file for submodules beneath the root of the directory tree
being compiled.  This fixes a regression introduced with Python 3.5.
..
.. bpo: 36144
.. date: 2020-02-25-09-28-06
.. nonce: Rbvvi7
.. section: Library
:class:`types.MappingProxyType` objects now support the merge (``|``)
operator from :pep:`584`.
..
.. bpo: 38691
.. date: 2020-02-23-02-09-03
.. nonce: oND8Sk
.. section: Library
The :mod:`importlib` module now ignores the :envvar:`PYTHONCASEOK`
environment variable when the :option:`-E` or :option:`-I` command line
options are being used.
..
.. bpo: 39719
.. date: 2020-02-21-22-35-57
.. nonce: 2jLy1C
.. section: Library
Remove :meth:`tempfile.SpooledTemporaryFile.softspace` as files no longer
have the ``softspace`` attribute in Python 3. Patch by Shantanu.
..
.. bpo: 39667
.. date: 2020-02-17-22-38-15
.. nonce: QuzEHH
.. section: Library
Improve pathlib.Path compatibility on zipfile.Path and correct performance
degradation as found in zipp 3.0.
..
.. bpo: 39638
.. date: 2020-02-15-20-38-11
.. nonce: wm_RS3
.. section: Library
Keep ASDL signatures in the docstrings for ``AST`` nodes. Patch by Batuhan
Taskaya
..
.. bpo: 39639
.. date: 2020-02-15-15-29-34
.. nonce: 3mqJjm
.. section: Library
Deprecated ``ast.Suite`` node class because it's no longer used. Patch by
Batuhan Taskaya.
..
.. bpo: 39609
.. date: 2020-02-11-19-45-31
.. nonce: dk40Uw
.. section: Library
Add thread_name_prefix to default asyncio executor
..
.. bpo: 39548
.. date: 2020-02-06-05-33-52
.. nonce: DF4FFe
.. section: Library
Fix handling of header in :class:`urllib.request.AbstractDigestAuthHandler`
when the optional ``qop`` parameter is not present.
..
.. bpo: 39509
.. date: 2020-02-01-00-03-06
.. nonce: -YxUSf
.. section: Library
HTTP status codes ``103 EARLY_HINTS`` and ``425 TOO_EARLY`` are added to
:class:`http.HTTPStatus`. Patch by Donghee Na.
..
.. bpo: 39507
.. date: 2020-01-31-14-24-05
.. nonce: 3oln1a
.. section: Library
Adding HTTP status 418 "I'm a Teapot" to HTTPStatus in http library. Patch
by Ross Rhodes.
..
.. bpo: 39495
.. date: 2020-01-30-07-02-02
.. nonce: 8LsIRN
.. section: Library
Remove default value from *attrs* parameter of
:meth:`xml.etree.ElementTree.TreeBuilder.start` for consistency between
Python and C implementations.
..
.. bpo: 38971
.. date: 2019-12-20-16-06-28
.. nonce: fKRYlF
.. section: Library
Open issue in the BPO indicated a desire to make the implementation of
codecs.open() at parity with io.open(), which implements a try/except to
assure file stream gets closed before an exception is raised.
..
.. bpo: 38641
.. date: 2019-10-30-15-31-09
.. nonce: HrTL9k
.. section: Library
Added starred expressions support to ``return`` and ``yield`` statements for
``lib2to3``. Patch by Vlad Emelianov.
..
.. bpo: 37534
.. date: 2019-08-20-00-02-37
.. nonce: TvjAUi
.. section: Library
When using minidom module to generate XML documents the ability to add
Standalone Document Declaration is added. All the changes are made to
generate a document in compliance with Extensible Markup Language (XML) 1.0
(Fifth Edition) W3C Recommendation (available here:
https://www.w3.org/TR/xml/#sec-prolog-dtd).
..
.. bpo: 34788
.. date: 2019-07-17-08-26-14
.. nonce: pwV1OK
.. section: Library
Add support for scoped IPv6 addresses to :mod:`ipaddress`. Patch by
Oleksandr Pavliuk.
..
.. bpo: 34822
.. date: 2018-09-27-19-31-47
.. nonce: EztBhL
.. section: Library
Simplified AST for subscription. Simple indices are now represented by their
value, extended slices are represented as tuples.  :mod:`ast` classes
``Index`` and ``ExtSlice`` are considered deprecated and will be removed in
future Python versions. In the meantime, ``Index(value)`` now returns a
``value`` itself, ``ExtSlice(slices)`` returns ``Tuple(slices, Load())``.
..
.. bpo: 39868
.. date: 2020-03-05-16-29-03
.. nonce: JQoHhO
.. section: Documentation
Updated the Language Reference for :pep:`572`.
..
.. bpo: 13790
.. date: 2020-02-28-14-39-25
.. nonce: hvLaRI
.. section: Documentation
Change 'string' to 'specification' in format doc.
..
.. bpo: 17422
.. date: 2020-02-27-17-35-27
.. nonce: eS1hVh
.. section: Documentation
The language reference no longer restricts default class namespaces to dicts
only.
..
.. bpo: 39530
.. date: 2020-02-23-13-26-40
.. nonce: _bCvzQ
.. section: Documentation
Fix misleading documentation about mixed-type numeric comparisons.
..
.. bpo: 39718
.. date: 2020-02-21-22-05-20
.. nonce: xtBoSi
.. section: Documentation
Update :mod:`token` documentation to reflect additions in Python 3.8
..
.. bpo: 39677
.. date: 2020-02-18-14-28-31
.. nonce: vNHqoX
.. section: Documentation
Changed operand name of **MAKE_FUNCTION** from *argc* to *flags* for module
:mod:`dis`
..
.. bpo: 40019
.. date: 2020-03-20-00-30-36
.. nonce: zOqHpQ
.. section: Tests
test_gdb now skips tests if it detects that gdb failed to read debug
information because the Python binary is optimized.
..
.. bpo: 27807
.. date: 2020-03-18-16-04-33
.. nonce: 9gKjET
.. section: Tests
``test_site.test_startup_imports()`` is now skipped if a path of
:data:`sys.path` contains a ``.pth`` file.
..
.. bpo: 26067
.. date: 2020-03-16-20-54-55
.. nonce: m18_VV
.. section: Tests
Do not fail test_shutil test_chown test when uid or gid of user cannot be
resolved to a name.
..
.. bpo: 39855
.. date: 2020-03-04-23-03-01
.. nonce: Ql5xv8
.. section: Tests
test_subprocess.test_user() now skips the test on an user name if the user
name doesn't exist. For example, skip the test if the user "nobody" doesn't
exist on Linux.
..
.. bpo: 39761
.. date: 2020-03-03-15-56-07
.. nonce: k10aGe
.. section: Build
Fix build with DTrace but without additional DFLAGS.
..
.. bpo: 39763
.. date: 2020-03-02-14-44-09
.. nonce: GGEwhH
.. section: Build
setup.py now uses a basic implementation of the :mod:`subprocess` module if
the :mod:`subprocess` module is not available: before required C extension
modules are built.
..
.. bpo: 1294959
.. date: 2020-02-06-18-08-25
.. nonce: AZPg4R
.. section: Build
Add ``--with-platlibdir`` option to the configure script: name of the
platform-specific library directory, stored in the new
:data:`sys.platlibdir` attribute. It is used to build the path of
platform-specific extension modules and the path of the standard library. It
is equal to ``"lib"`` on most platforms. On Fedora and SuSE, it is equal to
``"lib64"`` on 64-bit platforms. Patch by Jan Matějek, Matěj Cepl,
Charalampos Stratakis and Victor Stinner.
..
.. bpo: 39930
.. date: 2020-03-11-10-15-56
.. nonce: LGHw1j
.. section: Windows
Ensures the required :file:`vcruntime140.dll` is included in install
packages.
..
.. bpo: 39847
.. date: 2020-03-04-17-05-11
.. nonce: C3N2m3
.. section: Windows
Avoid hang when computer is hibernated whilst waiting for a mutex (for
lock-related objects from :mod:`threading`) around 49-day uptime.
..
.. bpo: 38597
.. date: 2020-03-01-15-04-54
.. nonce: MnHdYl
.. section: Windows
``distutils`` will no longer statically link :file:`vcruntime140.dll`
when a redistributable version is unavailable. All future releases of
CPython will include a copy of this DLL to ensure distributed extensions can
continue to load.
..
.. bpo: 38380
.. date: 2020-02-28-23-51-27
.. nonce: TpOBCj
.. section: Windows
Update Windows builds to use SQLite 3.31.1
..
.. bpo: 39789
.. date: 2020-02-28-22-46-09
.. nonce: 67XRoP
.. section: Windows
Update Windows release build machines to Visual Studio 2019 (MSVC 14.2).
..
.. bpo: 34803
.. date: 2020-02-25-18-43-34
.. nonce: S3VcS0
.. section: Windows
Package for nuget.org now includes repository reference and bundled icon
image.
..
.. bpo: 38380
.. date: 2020-02-28-23-51-47
.. nonce: u-ySyA
.. section: macOS
Update macOS builds to use SQLite 3.31.1
..
.. bpo: 27115
.. date: 2020-03-09-02-45-12
.. nonce: 8hSHMo
.. section: IDLE
For 'Go to Line', use a Query box subclass with IDLE standard behavior and
improved error checking.
..
.. bpo: 39885
.. date: 2020-03-08-14-27-36
.. nonce: 29ERiR
.. section: IDLE
Since clicking to get an IDLE context menu moves the cursor, any text
selection should be and now is cleared.
..
.. bpo: 39852
.. date: 2020-03-06-01-55-14
.. nonce: QjA1qF
.. section: IDLE
Edit "Go to line" now clears any selection, preventing accidental deletion.
It also updates Ln and Col on the status bar.
..
.. bpo: 39781
.. date: 2020-02-27-22-17-09
.. nonce: bbYBeL
.. section: IDLE
Selecting code context lines no longer causes a jump.
..
.. bpo: 36184
.. date: 2020-03-09-13-28-13
.. nonce: BMPJ0D
.. section: Tools/Demos
Port python-gdb.py to FreeBSD. python-gdb.py now checks for "take_gil"
function name to check if a frame tries to acquire the GIL, instead of
checking for "pthread_cond_timedwait" which is specific to Linux and can be
a different condition than the GIL.
..
.. bpo: 38080
.. date: 2019-09-18-13-49-56
.. nonce: Nbl7lF
.. section: Tools/Demos
Added support to fix ``getproxies`` in the :mod:`!lib2to3.fixes.fix_urllib`
module. Patch by José Roberto Meza Cabrera.
..
.. bpo: 40024
.. date: 2020-03-20-18-41-33
.. nonce: 9zHpve
.. section: C API
Add :c:func:`PyModule_AddType` helper function: add a type to a module.
Patch by Donghee Na.
..
.. bpo: 39946
.. date: 2020-03-20-17-05-52
.. nonce: 3NS-Ls
.. section: C API
Remove ``_PyRuntime.getframe`` hook and remove ``_PyThreadState_GetFrame``
macro which was an alias to ``_PyRuntime.getframe``. They were only exposed
by the internal C API. Remove also ``PyThreadFrameGetter`` type.
..
.. bpo: 39947
.. date: 2020-03-20-14-55-09
.. nonce: W7uCJ3
.. section: C API
Add :c:func:`PyThreadState_GetFrame` function: get the current frame of a
Python thread state.
..
.. bpo: 37207
.. date: 2020-03-14-01-56-03
.. nonce: R3jaTy
.. section: C API
Add _PyArg_NoKwnames helper function. Patch by Donghee Na.
..
.. bpo: 39947
.. date: 2020-03-13-18-10-58
.. nonce: gmEAaU
.. section: C API
Add :c:func:`PyThreadState_GetInterpreter`: get the interpreter of a Python
thread state.
..
.. bpo: 39947
.. date: 2020-03-13-17-43-00
.. nonce: 1Cu_d2
.. section: C API
Add :c:func:`PyInterpreterState_Get` function to the limited C API.
..
.. bpo: 35370
.. date: 2020-03-13-16-44-23
.. nonce: sXRA-r
.. section: C API
If :c:func:`PySys_Audit` fails in :c:func:`PyEval_SetProfile` or
:c:func:`PyEval_SetTrace`, log the error as an unraisable exception.
..
.. bpo: 39947
.. date: 2020-03-13-00-15-19
.. nonce: w3dIru
.. section: C API
Move the static inline function flavor of Py_EnterRecursiveCall() and
Py_LeaveRecursiveCall() to the internal C API: they access PyThreadState
attributes. The limited C API provides regular functions which hide
implementation details.
..
.. bpo: 39947
.. date: 2020-03-12-23-47-57
.. nonce: -nCdFV
.. section: C API
Py_TRASHCAN_BEGIN_CONDITION and Py_TRASHCAN_END macro no longer access
PyThreadState attributes, but call new private _PyTrash_begin() and
_PyTrash_end() functions which hide implementation details.
..
.. bpo: 39884
.. date: 2020-03-12-00-27-26
.. nonce: CGOJBO
.. section: C API
:c:func:`PyDescr_NewMethod` and :c:func:`PyCFunction_NewEx` now include the
method name in the SystemError "bad call flags" error message to ease debug.
..
.. bpo: 39877
.. date: 2020-03-10-00-18-16
.. nonce: GOYtIm
.. section: C API
Deprecated :c:func:`!PyEval_InitThreads` and
:c:func:`!PyEval_ThreadsInitialized`. Calling :c:func:`!PyEval_InitThreads`
now does nothing.
..
.. bpo: 38249
.. date: 2020-03-09-20-27-19
.. nonce: IxYbQy
.. section: C API
:c:macro:`Py_UNREACHABLE` is now implemented with
``__builtin_unreachable()`` and analogs in release mode.
..
.. bpo: 38643
.. date: 2020-03-08-22-56-22
.. nonce: k2ixx6
.. section: C API
:c:func:`PyNumber_ToBase` now raises a :exc:`SystemError` instead of
crashing when called with invalid base.
..
.. bpo: 39882
.. date: 2020-03-06-23-56-04
.. nonce: Iqhcqm
.. section: C API
The :c:func:`Py_FatalError` function is replaced with a macro which logs
automatically the name of the current function, unless the
``Py_LIMITED_API`` macro is defined.
..
.. bpo: 39824
.. date: 2020-03-02-11-29-45
.. nonce: 71_ZMn
.. section: C API
Extension modules: :c:member:`~PyModuleDef.m_traverse`,
:c:member:`~PyModuleDef.m_clear` and :c:member:`~PyModuleDef.m_free`
functions of :c:type:`PyModuleDef` are no longer called if the module state
was requested but is not allocated yet. This is the case immediately after
the module is created and before the module is executed
(:c:data:`Py_mod_exec` function). More precisely, these functions are not
called if :c:member:`~PyModuleDef.m_size` is greater than 0 and the module
state (as returned by :c:func:`PyModule_GetState`) is ``NULL``.
Extension modules without module state (``m_size <= 0``) are not affected.
..
.. bpo: 38913
.. date: 2020-02-25-20-10-34
.. nonce: siF1lS
.. section: C API
Fixed segfault in ``Py_BuildValue()`` called with a format containing "#"
and undefined PY_SSIZE_T_CLEAN whwn an exception is set.
..
.. bpo: 38500
.. date: 2019-11-22-14-06-28
.. nonce: nPEdjH
.. section: C API
Add a private API to get and set the frame evaluation function: add
:c:func:`_PyInterpreterState_GetEvalFrameFunc` and
:c:func:`_PyInterpreterState_SetEvalFrameFunc` C functions. The
:c:type:`_PyFrameEvalFunction` function type now takes a *tstate* parameter.

.. bpo: 0
.. date: 2018-06-27
.. no changes: True
.. nonce: IWyX1H
.. release date: 2018-06-27
.. section: Library
There were no new changes in version 3.6.6.

.. date: 2024-11-28-15-55-48
.. gh-issue: 127353
.. nonce: i-XOXg
.. release date: 2024-12-17
.. section: Windows
Allow to force color output on Windows using environment variables. Patch by
Andrey Efremov.
..
.. date: 2024-10-31-09-46-53
.. gh-issue: 125729
.. nonce: KdKVLa
.. section: Windows
Makes the presence of the :mod:`turtle` module dependent on the Tcl/Tk
installer option. Previously, the module was always installed but would be
unusable without Tcl/Tk.
..
.. date: 2024-11-16-20-47-20
.. gh-issue: 126700
.. nonce: ayrHv4
.. section: Tools/Demos
Add support for multi-argument :mod:`gettext` functions in
:program:`pygettext.py`.
..
.. date: 2024-12-13-13-41-34
.. gh-issue: 127906
.. nonce: NuRHlB
.. section: Tests
Test the limited C API in test_cppext. Patch by Victor Stinner.
..
.. date: 2024-12-09-12-35-44
.. gh-issue: 127637
.. nonce: KLx-9I
.. section: Tests
Add tests for the :mod:`dis` command-line interface. Patch by Bénédikt Tran.
..
.. date: 2024-12-04-15-03-24
.. gh-issue: 126925
.. nonce: uxAMK-
.. section: Tests
iOS test results are now streamed during test execution, and the deprecated
xcresulttool is no longer used.
..
.. date: 2024-11-21-02-03-48
.. gh-issue: 127076
.. nonce: a3avV1
.. section: Tests
Disable strace based system call tests when LD_PRELOAD is set.
..
.. date: 2024-11-20-18-49-01
.. gh-issue: 127076
.. nonce: DHnXxo
.. section: Tests
Filter out memory-related ``mmap``, ``munmap``, and ``mprotect``  calls from
file-related ones when testing :mod:`io` behavior using strace.
..
.. date: 2024-12-05-21-35-19
.. gh-issue: 127655
.. nonce: xpPoOf
.. section: Security
Fixed the :class:`!asyncio.selector_events._SelectorSocketTransport`
transport not pausing writes for the protocol when the buffer reaches the
high water mark when using :meth:`asyncio.WriteTransport.writelines`.
..
.. date: 2024-12-13-22-20-54
.. gh-issue: 126907
.. nonce: fWRL_R
.. section: Library
Fix crash when using :mod:`atexit` concurrently on the :term:`free-threaded
<free threading>` build.
..
.. date: 2024-12-12-16-59-42
.. gh-issue: 127870
.. nonce: _NFG-3
.. section: Library
Detect recursive calls in ctypes ``_as_parameter_`` handling. Patch by
Victor Stinner.
..
.. date: 2024-12-08-08-36-18
.. gh-issue: 127732
.. nonce: UEKxoa
.. section: Library
The :mod:`platform` module now correctly detects Windows Server 2025.
..
.. date: 2024-12-07-23-06-44
.. gh-issue: 126789
.. nonce: 4dqfV1
.. section: Library
Fixed :func:`sysconfig.get_config_vars`, :func:`sysconfig.get_paths`, and
siblings, returning outdated cached data if the value  of :data:`sys.prefix`
or :data:`sys.exec_prefix` changes. Overwriting :data:`sys.prefix` or
:data:`sys.exec_prefix` still is discouraged, as that might break other
parts of the code.
..
.. date: 2024-12-07-15-28-31
.. gh-issue: 127718
.. nonce: 9dpLfi
.. section: Library
Add colour to :mod:`test.regrtest` output. Patch by Hugo van Kemenade.
..
.. date: 2024-12-06-17-28-55
.. gh-issue: 127610
.. nonce: ctv_NP
.. section: Library
Added validation for more than one var-positional or var-keyword parameters
in :class:`inspect.Signature`. Patch by Maxim Ageev.
..
.. date: 2024-12-05-10-14-52
.. gh-issue: 127627
.. nonce: fgCHOZ
.. section: Library
Added ``posix._emscripten_debugger()`` to help with debugging the test suite
on the Emscripten target.
..
.. date: 2024-12-04-15-04-12
.. gh-issue: 126821
.. nonce: lKCLVV
.. section: Library
macOS and iOS apps can now choose to redirect stdout and stderr to the
system log during interpreter configuration.
..
.. date: 2024-12-04-11-01-16
.. gh-issue: 93312
.. nonce: 9sB-Qw
.. section: Library
Include ``<sys/pidfd.h>`` to get ``os.PIDFD_NONBLOCK`` constant. Patch by
Victor Stinner.
..
.. date: 2024-12-01-23-18-43
.. gh-issue: 127481
.. nonce: K36AoP
.. section: Library
Add the ``EPOLLWAKEUP`` constant to the :mod:`select` module.
..
.. date: 2024-12-01-22-28-41
.. gh-issue: 127065
.. nonce: tFpRer
.. section: Library
Make :func:`operator.methodcaller` thread-safe and re-entrant safe.
..
.. date: 2024-11-30-21-46-15
.. gh-issue: 127321
.. nonce: M78fBv
.. section: Library
:func:`pdb.set_trace` will not stop at an opcode that does not have an
associated line number anymore.
..
.. date: 2024-11-29-23-02-43
.. gh-issue: 127429
.. nonce: dQf2w4
.. section: Library
Fixed bug where, on cross-builds, the :mod:`sysconfig` POSIX data was being
generated with the host Python's ``Makefile``. The data is now generated
from current build's ``Makefile``.
..
.. date: 2024-11-29-14-45-26
.. gh-issue: 127413
.. nonce: z11AUc
.. section: Library
Add the :option:`dis --specialized` command-line option to show specialized
bytecode. Patch by Bénédikt Tran.
..
.. date: 2024-11-29-00-15-59
.. gh-issue: 125413
.. nonce: WCN0vv
.. section: Library
Revert addition of :meth:`!pathlib.Path.scandir`. This method was added in
3.14.0a2. The optimizations remain for file system paths, but other
subclasses should only have to implement :meth:`pathlib.Path.iterdir`.
..
.. date: 2024-11-28-14-14-46
.. gh-issue: 127257
.. nonce: n6-jU9
.. section: Library
In :mod:`ssl`, system call failures that OpenSSL reports using
``ERR_LIB_SYS`` are now raised as :exc:`OSError`.
..
.. date: 2024-11-27-17-04-38
.. gh-issue: 59705
.. nonce: sAGyvs
.. section: Library
On Linux, :class:`threading.Thread` now sets the thread name to the
operating system. Patch by Victor Stinner.
..
.. date: 2024-11-27-16-06-10
.. gh-issue: 127303
.. nonce: asqkgh
.. section: Library
Publicly expose :data:`~token.EXACT_TOKEN_TYPES` in :attr:`!token.__all__`.
..
.. date: 2024-11-27-14-23-02
.. gh-issue: 127331
.. nonce: 9sNEC9
.. section: Library
:mod:`ssl` can show descriptions for errors added in OpenSSL 3.4.
..
.. date: 2024-11-27-14-06-35
.. gh-issue: 123967
.. nonce: wxUmnW
.. section: Library
Fix faulthandler for trampoline frames. If the top-most frame is a
trampoline frame, skip it. Patch by Victor Stinner.
..
.. date: 2024-11-26-17-42-00
.. gh-issue: 127178
.. nonce: U8hxjc
.. section: Library
A ``_sysconfig_vars_(...).json`` file is now shipped in the standard library
directory. It contains the output of :func:`sysconfig.get_config_vars` on
the default environment encoded as JSON data. This is an implementation
detail, and may change at any time.
..
.. date: 2024-11-25-19-04-10
.. gh-issue: 127072
.. nonce: -c284K
.. section: Library
Remove outdated ``socket.NETLINK_*`` constants not present in Linux kernels
beyond 2.6.17.
..
.. date: 2024-11-25-15-02-44
.. gh-issue: 127255
.. nonce: UXeljc
.. section: Library
The :func:`~ctypes.CopyComPointer` function is now public. Previously, this
was private and only available in ``_ctypes``.
..
.. date: 2024-11-24-14-20-17
.. gh-issue: 127182
.. nonce: WmfY2g
.. section: Library
Fix :meth:`!io.StringIO.__setstate__` crash, when :const:`None` was passed
as the first value.
..
.. date: 2024-11-24-12-41-31
.. gh-issue: 127217
.. nonce: UAXGFr
.. section: Library
Fix :func:`urllib.request.pathname2url` for paths starting with multiple
slashes on Posix.
..
.. date: 2024-11-23-12-25-06
.. gh-issue: 125866
.. nonce: wEOP66
.. section: Library
:func:`urllib.request.pathname2url` now adds an empty authority when
generating a URL for a path that begins with exactly one slash. For example,
the path ``/etc/hosts`` is converted to the scheme-less URL
``///etc/hosts``. As a result of this change, URLs without authorities are
only generated for relative paths.
..
.. date: 2024-11-23-00-17-29
.. gh-issue: 127221
.. nonce: OSXdFE
.. section: Library
Add colour to :mod:`unittest` output. Patch by Hugo van Kemenade.
..
.. date: 2024-11-22-10-42-34
.. gh-issue: 127035
.. nonce: UnbDlr
.. section: Library
Fix :mod:`shutil.which` on Windows. Now it looks at direct match if and only
if the command ends with a PATHEXT extension or X_OK is not in mode. Support
extensionless files if "." is in PATHEXT. Support PATHEXT extensions that
end with a dot.
..
.. date: 2024-11-22-09-23-41
.. gh-issue: 122273
.. nonce: H8M6fd
.. section: Library
Support PyREPL history on Windows. Patch by devdanzin and Victor Stinner.
..
.. date: 2024-11-22-04-49-31
.. gh-issue: 125866
.. nonce: TUtvPK
.. section: Library
:func:`urllib.request.pathname2url` and :func:`~urllib.request.url2pathname`
no longer convert Windows drive letters to uppercase.
..
.. date: 2024-11-22-03-40-02
.. gh-issue: 127078
.. nonce: gI_PaP
.. section: Library
Fix issue where :func:`urllib.request.url2pathname` failed to discard an
extra slash before a UNC drive in the URL path on Windows.
..
.. date: 2024-11-22-02-31-55
.. gh-issue: 126766
.. nonce: jfkhBH
.. section: Library
Fix issue where :func:`urllib.request.url2pathname` failed to discard any
'localhost' authority present in the URL.
..
.. date: 2024-11-21-16-23-16
.. gh-issue: 127065
.. nonce: cfL1zd
.. section: Library
Fix crash when calling a :func:`operator.methodcaller` instance from
multiple threads in the free threading build.
..
.. date: 2024-11-21-06-03-46
.. gh-issue: 127090
.. nonce: yUYwdh
.. section: Library
Fix value of :attr:`urllib.response.addinfourl.url` for ``file:`` URLs that
express relative paths and absolute Windows paths. The canonical URL
generated by :func:`urllib.request.pathname2url` is now used.
..
.. date: 2024-11-20-21-20-56
.. gh-issue: 126992
.. nonce: RbU0FZ
.. section: Library
Fix LONG and INT opcodes to only use base 10 for string to integer
conversion in :mod:`pickle`.
..
.. date: 2024-11-20-16-58-59
.. gh-issue: 126997
.. nonce: 0PI41Y
.. section: Library
Fix support of STRING and GLOBAL opcodes with non-ASCII arguments in
:mod:`pickletools`. :func:`pickletools.dis` now outputs non-ASCII bytes in
STRING, BINSTRING and SHORT_BINSTRING arguments as escaped (``\xXX``).
..
.. date: 2024-11-20-11-37-08
.. gh-issue: 126316
.. nonce: ElkZmE
.. section: Library
:mod:`grp`: Make :func:`grp.getgrall` thread-safe by adding a mutex. Patch
by Victor Stinner.
..
.. date: 2024-11-20-08-54-11
.. gh-issue: 126618
.. nonce: ef_53g
.. section: Library
Fix the representation of :class:`itertools.count` objects when the count
value is :data:`sys.maxsize`.
..
.. date: 2024-11-19-14-34-05
.. gh-issue: 126615
.. nonce: LOskwi
.. section: Library
The :exc:`~ctypes.COMError` exception is now public. Previously, this was
private and only available in ``_ctypes``.
..
.. date: 2024-11-18-23-42-06
.. gh-issue: 126985
.. nonce: 7XplY9
.. section: Library
When running under a virtual environment with the :mod:`site` disabled (see
:option:`-S`), :data:`sys.prefix` and :data:`sys.base_prefix` will now point
to the virtual environment, instead of the base installation.
..
.. date: 2024-11-18-23-18-27
.. gh-issue: 112192
.. nonce: DRdRgP
.. section: Library
In the :mod:`trace` module, increase the coverage precision (``cov%``) to
one decimal.
..
.. date: 2024-11-18-22-02-47
.. gh-issue: 118761
.. nonce: GQKD_J
.. section: Library
Improve import time of :mod:`mimetypes` by around 11-16 times. Patch by Hugo
van Kemenade.
..
.. date: 2024-11-18-19-03-46
.. gh-issue: 126947
.. nonce: NiDYUe
.. section: Library
Raise :exc:`TypeError` in :meth:`!_pydatetime.timedelta.__new__` if the
passed arguments are not :class:`int` or :class:`float`, so that the Python
implementation is in line with the C implementation.
..
.. date: 2024-11-18-16-43-11
.. gh-issue: 126946
.. nonce: 52Ou-B
.. section: Library
Improve the :exc:`~getopt.GetoptError` error message when a long option
prefix matches multiple accepted options in :func:`getopt.getopt` and
:func:`getopt.gnu_getopt`.
..
.. date: 2024-11-16-10-52-48
.. gh-issue: 126899
.. nonce: GFnfBt
.. section: Library
Make tkinter widget methods :meth:`!after` and :meth:`!after_idle` accept
arguments passed by keyword.
..
.. date: 2024-11-15-01-50-36
.. gh-issue: 85168
.. nonce: bP8VIN
.. section: Library
Fix issue where :func:`urllib.request.url2pathname` and
:func:`~urllib.request.pathname2url` always used UTF-8 when quoting and
unquoting file URIs. They now use the :term:`filesystem encoding and error
handler`.
..
.. date: 2024-11-13-19-15-18
.. gh-issue: 126780
.. nonce: ZZqJvI
.. section: Library
Fix :func:`os.path.normpath` for drive-relative paths on Windows.
..
.. date: 2024-11-13-10-44-25
.. gh-issue: 126775
.. nonce: a3ubjh
.. section: Library
Make :func:`linecache.checkcache` thread safe and GC re-entrancy safe.
..
.. date: 2024-11-12-20-05-09
.. gh-issue: 126601
.. nonce: Nj7bA9
.. section: Library
Fix issue where :func:`urllib.request.pathname2url` raised :exc:`OSError`
when given a Windows path containing a colon character not following a drive
letter, such as before an NTFS alternate data stream.
..
.. date: 2024-11-12-13-14-47
.. gh-issue: 126727
.. nonce: 5Eqfqd
.. section: Library
``locale.nl_langinfo(locale.ERA)`` now returns multiple era description
segments separated by semicolons. Previously it only returned the first
segment on platforms with Glibc.
..
.. date: 2024-11-04-22-02-30
.. gh-issue: 85046
.. nonce: Y5d_ZN
.. section: Library
Add :data:`~errno.EHWPOISON` error code to :mod:`errno`.
..
.. date: 2024-10-28-19-49-18
.. gh-issue: 118201
.. nonce: v41XXh
.. section: Library
Fixed intermittent failures of :any:`os.confstr`, :any:`os.pathconf` and
:any:`os.sysconf` on iOS and Android.
..
.. date: 2024-10-23-20-05-54
.. gh-issue: 86463
.. nonce: jvFTI_
.. section: Library
The ``usage`` parameter of :class:`argparse.ArgumentParser` no longer
affects the default value of the ``prog`` parameter in subparsers.
..
.. date: 2024-09-13-18-24-27
.. gh-issue: 124008
.. nonce: XaiPQx
.. section: Library
Fix possible crash (in debug build), incorrect output or returning incorrect
value from raw binary ``write()`` when writing to console on Windows.
..
.. date: 2024-08-27-18-58-01
.. gh-issue: 123401
.. nonce: t4-FpI
.. section: Library
The :mod:`http.cookies` module now supports parsing obsolete :rfc:`850` date
formats, in accordance with :rfc:`9110` requirements. Patch by Nano Zheng.
..
.. date: 2024-07-30-11-37-40
.. gh-issue: 122431
.. nonce: lAzVtu
.. section: Library
:func:`readline.append_history_file` now raises a :exc:`ValueError` when
given a negative value.
..
.. date: 2024-07-29-15-20-30
.. gh-issue: 122356
.. nonce: wKCmFx
.. section: Library
Guarantee that the position of a file-like object passed to
:func:`zipfile.is_zipfile` is left untouched after the call. Patch by
Bénédikt Tran.
..
.. date: 2024-07-25-18-06-51
.. gh-issue: 122288
.. nonce: -_xxOR
.. section: Library
Improve the performances of :func:`fnmatch.translate` by a factor 1.7. Patch
by Bénédikt Tran.
..
.. date: 2023-02-15-23-54-42
.. gh-issue: 88110
.. nonce: KU6erv
.. section: Library
Fixed :class:`multiprocessing.Process` reporting a ``.exitcode`` of 1 even
on success when using the ``"fork"`` start method while using a
:class:`concurrent.futures.ThreadPoolExecutor`.
..
.. date: 2022-11-10-17-16-45
.. gh-issue: 97514
.. nonce: kzA0zl
.. section: Library
Authentication was added to the :mod:`multiprocessing` forkserver start
method control socket so that only processes with the authentication key
generated by the process that spawned the forkserver can control it.  This
is an enhancement over the other :gh:`97514` fixes so that access is no
longer limited only by filesystem permissions.
The file descriptor exchange of control pipes with the forked worker process
now requires an explicit acknowledgement byte to be sent over the socket
after the exchange on all forkserver supporting platforms. That makes
testing the above much easier.
..
.. date: 2024-11-27-22-56-48
.. gh-issue: 127347
.. nonce: xyddWS
.. section: Documentation
Publicly expose :func:`traceback.print_list` in :attr:`!traceback.__all__`.
..
.. date: 2024-12-10-21-08-05
.. gh-issue: 127740
.. nonce: 0tWC9h
.. section: Core and Builtins
Fix error message in :func:`bytes.fromhex` when given an odd number of
digits to properly indicate that an even number of hexadecimal digits is
required.
..
.. date: 2024-12-09-11-29-10
.. gh-issue: 127058
.. nonce: pqtBcZ
.. section: Core and Builtins
``PySequence_Tuple`` now creates the resulting tuple atomically, preventing
partially created tuples being visible to the garbage collector or through
``gc.get_referrers()``
..
.. date: 2024-12-07-13-06-09
.. gh-issue: 127599
.. nonce: tXCZb_
.. section: Core and Builtins
Fix statistics for increments of object reference counts (in particular,
when a reference count was increased by more than 1 in a single operation).
..
.. date: 2024-12-06-01-09-40
.. gh-issue: 127651
.. nonce: 80cm6j
.. section: Core and Builtins
When raising :exc:`ImportError` for missing symbols in ``from`` imports, use
``__file__`` in the error message if ``__spec__.origin`` is not a location
..
.. date: 2024-12-05-19-25-00
.. gh-issue: 127582
.. nonce: ogUY2a
.. section: Core and Builtins
Fix non-thread-safe object resurrection when calling finalizers and watcher
callbacks in the free threading build.
..
.. date: 2024-12-04-09-52-08
.. gh-issue: 127434
.. nonce: RjkGT_
.. section: Core and Builtins
The iOS compiler shims can now accept arguments with spaces.
..
.. date: 2024-12-03-21-07-06
.. gh-issue: 127536
.. nonce: 3jMMrT
.. section: Core and Builtins
Add missing locks around some list assignment operations in the free
threading build.
..
.. date: 2024-11-30-23-35-45
.. gh-issue: 127085
.. nonce: KLKylb
.. section: Core and Builtins
Fix race when exporting a buffer from a :class:`memoryview` object on the
:term:`free-threaded <free threading>` build.
..
.. date: 2024-11-25-05-15-21
.. gh-issue: 127238
.. nonce: O8wkH-
.. section: Core and Builtins
Correct error message for :func:`sys.set_int_max_str_digits`.
..
.. date: 2024-11-24-07-01-28
.. gh-issue: 113841
.. nonce: WFg-Bu
.. section: Core and Builtins
Fix possible undefined behavior division by zero in :class:`complex`'s
:c:func:`_Py_c_pow`.
..
.. date: 2024-11-23-04-54-42
.. gh-issue: 127133
.. nonce: WMoJjF
.. section: Library
Calling :meth:`argparse.ArgumentParser.add_argument_group` on an argument
group, and calling :meth:`argparse.ArgumentParser.add_argument_group` or
:meth:`argparse.ArgumentParser.add_mutually_exclusive_group` on a mutually
exclusive group now raise exceptions. This nesting was never supported,
often failed to work correctly, and was unintentionally exposed through
inheritance. This functionality has been deprecated since Python 3.11.
..
.. date: 2024-11-21-16-13-52
.. gh-issue: 126491
.. nonce: 0YvL94
.. section: Core and Builtins
Add a marking phase to the GC. All objects that can be transitively reached
from builtin modules or the stacks are marked as reachable before cycle
detection. This reduces the amount of work done by the GC by approximately
half.
..
.. date: 2024-11-19-21-49-58
.. gh-issue: 127020
.. nonce: 5vvI17
.. section: Core and Builtins
Fix a crash in the free threading build when :c:func:`PyCode_GetCode`,
:c:func:`PyCode_GetVarnames`, :c:func:`PyCode_GetCellvars`, or
:c:func:`PyCode_GetFreevars` were called from multiple threads at the same
time.
..
.. date: 2024-11-19-17-17-32
.. gh-issue: 127010
.. nonce: 9Cl4bb
.. section: Core and Builtins
Simplify GC tracking of dictionaries. All dictionaries are tracked when
created, rather than being lazily tracked when a trackable object was added
to them. This simplifies the code considerably and results in a slight
speedup.
..
.. date: 2024-11-18-23-18-17
.. gh-issue: 126980
.. nonce: r8QHdi
.. section: Core and Builtins
Fix :meth:`~object.__buffer__` of :class:`bytearray` crashing when
:attr:`~inspect.BufferFlags.READ` or :attr:`~inspect.BufferFlags.WRITE` are
passed as flags.
..
.. date: 2024-11-17-21-35-55
.. gh-issue: 126937
.. nonce: qluVM0
.. section: Core and Builtins
Fix :exc:`TypeError` when a :class:`ctypes.Structure` has a field size that
doesn't fit into an unsigned 16-bit integer. Instead, the maximum number of
*bits* is :data:`sys.maxsize`.
..
.. date: 2024-11-16-22-37-46
.. gh-issue: 126868
.. nonce: yOoHSY
.. section: Core and Builtins
Increase performance of :class:`int` by adding a freelist for compact ints.
..
.. date: 2024-11-16-11-11-35
.. gh-issue: 126881
.. nonce: ijofLZ
.. section: Core and Builtins
Fix crash in finalization of dtoa state. Patch by Kumar Aditya.
..
.. date: 2024-11-15-16-39-37
.. gh-issue: 126892
.. nonce: QR6Yo3
.. section: Core and Builtins
Require cold or invalidated code to "warm up" before being JIT compiled
again.
..
.. date: 2024-11-07-21-48-23
.. gh-issue: 126091
.. nonce: ETaRGE
.. section: Core and Builtins
Ensure stack traces are complete when throwing into a generator chain that
ends in a custom generator.
..
.. date: 2024-10-27-04-47-28
.. gh-issue: 126024
.. nonce: XCQSqT
.. section: Core and Builtins
Optimize decoding of short UTF-8 sequences containing non-ASCII characters
by approximately 15%.
..
.. date: 2024-10-14-13-28-16
.. gh-issue: 125420
.. nonce: hNKixM
.. section: Core and Builtins
Add :meth:`memoryview.index` to :class:`memoryview` objects. Patch by
Bénédikt Tran.
..
.. date: 2024-10-14-12-34-51
.. gh-issue: 125420
.. nonce: jABXoZ
.. section: Core and Builtins
Add :meth:`memoryview.count` to :class:`memoryview` objects. Patch by
Bénédikt Tran.
..
.. date: 2024-09-25-21-50-23
.. gh-issue: 124470
.. nonce: pFr3_d
.. section: Core and Builtins
Fix crash in free-threaded builds when replacing object dictionary while
reading attribute on another thread
..
.. date: 2024-08-03-14-02-27
.. gh-issue: 69639
.. nonce: mW3iKq
.. section: Core and Builtins
Implement mixed-mode arithmetic rules combining real and complex numbers as
specified by C standards since C99.  Patch by Sergey B Kirpichev.
..
.. date: 2024-06-04-08-26-25
.. gh-issue: 120010
.. nonce: _z-AWz
.. section: Core and Builtins
Correct invalid corner cases which resulted in ``(nan+nanj)`` output in
complex multiplication, e.g., ``(1e300+1j)*(nan+infj)``.  Patch by Sergey B
Kirpichev.
..
.. date: 2023-09-22-21-01-56
.. gh-issue: 109746
.. nonce: 32MHt9
.. section: Core and Builtins
If :func:`!_thread.start_new_thread` fails to start a new thread, it deletes
its state from interpreter and thus avoids its repeated cleanup on
finalization.
..
.. date: 2024-12-16-07-12-15
.. gh-issue: 127896
.. nonce: HmI9pk
.. section: C API
The previously undocumented function :c:func:`PySequence_In` is :term:`soft
deprecated`. Use :c:func:`PySequence_Contains` instead.
..
.. date: 2024-12-10-14-25-22
.. gh-issue: 127791
.. nonce: YRw4GU
.. section: C API
Fix loss of callbacks after more than one call to
:c:func:`PyUnstable_AtExit`.
..
.. date: 2024-12-06-16-53-34
.. gh-issue: 127691
.. nonce: k_Jitp
.. section: C API
The :ref:`Unicode Exception Objects <unicodeexceptions>` C API now raises a
:exc:`TypeError` if its exception argument is not a :exc:`UnicodeError`
object. Patch by Bénédikt Tran.
..
.. date: 2024-12-02-16-10-36
.. gh-issue: 123378
.. nonce: Q6YRwe
.. section: C API
Ensure that the value of :attr:`UnicodeEncodeError.end <UnicodeError.end>`
retrieved by :c:func:`PyUnicodeEncodeError_GetEnd` lies in ``[min(1,
objlen), max(min(1, objlen), objlen)]`` where *objlen* is the length of
:attr:`UnicodeEncodeError.object <UnicodeError.object>`. Similar arguments
apply to :exc:`UnicodeDecodeError` and :exc:`UnicodeTranslateError` and
their corresponding C interface. Patch by Bénédikt Tran.
..
.. date: 2024-11-26-22-06-10
.. gh-issue: 127314
.. nonce: SsRrIu
.. section: C API
Improve error message when calling the C API without an active thread state
on the :term:`free-threaded <free threading>` build.
..
.. date: 2024-08-27-09-07-56
.. gh-issue: 123378
.. nonce: JJ6n_u
.. section: C API
Ensure that the value of :attr:`UnicodeEncodeError.start
<UnicodeError.start>` retrieved by :c:func:`PyUnicodeEncodeError_GetStart`
lies in ``[0, max(0, objlen - 1)]`` where *objlen* is the length of
:attr:`UnicodeEncodeError.object <UnicodeError.object>`. Similar arguments
apply to :exc:`UnicodeDecodeError` and :exc:`UnicodeTranslateError` and
their corresponding C interface. Patch by Bénédikt Tran.
..
.. date: 2024-08-12-10-15-19
.. gh-issue: 109523
.. nonce: S2c3fi
.. section: C API
Reading text from a non-blocking stream with ``read`` may now raise a
:exc:`BlockingIOError` if the operation cannot immediately return bytes.
..
.. date: 2024-07-03-17-26-53
.. gh-issue: 102471
.. nonce: XpmKYk
.. section: C API
Add a new import and export API for Python :class:`int` objects
(:pep:`757`):
* :c:func:`PyLong_GetNativeLayout`;
* :c:func:`PyLong_Export`;
* :c:func:`PyLong_FreeExport`;
* :c:func:`PyLongWriter_Create`;
* :c:func:`PyLongWriter_Finish`;
* :c:func:`PyLongWriter_Discard`.
Patch by Victor Stinner.
..
.. date: 2024-07-03-13-39-13
.. gh-issue: 121058
.. nonce: MKi1MV
.. section: C API
``PyThreadState_Clear()`` now warns (and calls ``sys.excepthook``) if the
thread state still has an active exception.
..
.. date: 2024-12-12-17-21-45
.. gh-issue: 127865
.. nonce: 30GDzs
.. section: Build
Fix build failure on systems without thread-locals support.
..
.. date: 2024-12-06-12-47-52
.. gh-issue: 127629
.. nonce: tD-ERQ
.. section: Build
Emscripten builds now include ctypes support.
..
.. date: 2024-11-30-16-36-09
.. gh-issue: 127111
.. nonce: QI9mMZ
.. section: Build
Updated the Emscripten web example to use ES6 modules and be built into a
distinct ``web_example`` subfolder.
..
.. date: 2024-11-22-08-46-46
.. gh-issue: 115869
.. nonce: UVLSKd
.. section: Build
Make ``jit_stencils.h`` (which is produced during JIT builds) reproducible.
..
.. date: 2024-11-20-17-12-40
.. gh-issue: 126898
.. nonce: I2zILt
.. section: Build
The Emscripten build of Python is now based on ES6 modules.

.. date: 2024-04-04-13-42-59
.. gh-issue: 117494
.. nonce: GPQH64
.. release date: 2024-04-09
.. section: Core and Builtins
Refactored the instruction sequence data structure out of compile.c into
instruction_sequence.c.
..
.. date: 2024-04-03-13-44-04
.. gh-issue: 116968
.. nonce: zgcdG2
.. section: Core and Builtins
Introduce a unified 16-bit backoff counter type (``_Py_BackoffCounter``),
shared between the Tier 1 adaptive specializer and the Tier 2 optimizer. The
API used for adaptive specialization counters is changed but the behavior is
(supposed to be) identical.
The behavior of the Tier 2 counters is changed:
* There are no longer dynamic thresholds (we never varied these).
* All counters now use the same exponential backoff.
* The counter for ``JUMP_BACKWARD`` starts counting down from 16.
* The ``temperature`` in side exits starts counting down from 64.
..
.. date: 2024-04-03-09-49-15
.. gh-issue: 117431
.. nonce: WAqRgc
.. section: Core and Builtins
Improve the performance of the following :class:`bytes` and
:class:`bytearray` methods by adapting them to the :c:macro:`METH_FASTCALL`
calling convention:
* :meth:`!endswith`
* :meth:`!startswith`
..
.. date: 2024-04-02-17-37-35
.. gh-issue: 117431
.. nonce: vDKAOn
.. section: Core and Builtins
Improve the performance of the following :class:`str` methods by adapting
them to the :c:macro:`METH_FASTCALL` calling convention:
* :meth:`~str.count`
* :meth:`~str.endswith`
* :meth:`~str.find`
* :meth:`~str.index`
* :meth:`~str.rfind`
* :meth:`~str.rindex`
* :meth:`~str.startswith`
..
.. date: 2024-04-02-10-04-57
.. gh-issue: 117411
.. nonce: YdyVmG
.. section: Core and Builtins
Move ``PyFutureFeatures`` to an internal header and make it private.
..
.. date: 2024-04-02-06-16-49
.. gh-issue: 109120
.. nonce: X485oN
.. section: Core and Builtins
Added handle of incorrect star expressions, e.g ``f(3, *)``. Patch by
Grigoryev Semyon
..
.. date: 2024-03-26-17-22-38
.. gh-issue: 117266
.. nonce: Kwh79O
.. section: Core and Builtins
Fix crashes for certain user-created subclasses of :class:`ast.AST`. Such
classes are now expected to set the ``_field_types`` attribute.
..
.. date: 2024-03-25-17-04-54
.. gh-issue: 99108
.. nonce: 8bjdO6
.. section: Core and Builtins
Updated the :mod:`hashlib` built-in `HACL\* project`_ C code from upstream
that we use for many implementations when they are not present via OpenSSL
in a given build.  This also avoids the rare potential for a C symbol name
one definition rule linking issue.
.. _HACL\* project: https://github.com/hacl-star/hacl-star
..
.. date: 2024-03-25-12-51-12
.. gh-issue: 117108
.. nonce: tNqDEo
.. section: Core and Builtins
Change the old space bit of objects in the young generation from 0 to
gcstate->visited, so that any objects created during GC will have the old
bit set correctly if they get moved into the old generation.
..
.. date: 2024-03-21-12-10-11
.. gh-issue: 117108
.. nonce: _6jIrB
.. section: Core and Builtins
The cycle GC now chooses the size of increments based on the total heap
size, instead of the rate of object creation. This ensures that it can keep
up with growing heaps.
..
.. date: 2024-03-13-16-55-25
.. gh-issue: 116735
.. nonce: o3w6y8
.. section: Core and Builtins
For ``INSTRUMENTED_CALL_FUNCTION_EX``, set ``arg0`` to
``sys.monitoring.MISSING`` instead of ``None`` for :monitoring-event:`CALL`
event.
..
.. date: 2024-03-12-20-31-57
.. gh-issue: 113964
.. nonce: bJppzg
.. section: Core and Builtins
Starting new threads and process creation through :func:`os.fork` are now
only prevented once all non-daemon threads exit.
..
.. date: 2024-03-11-22-05-56
.. gh-issue: 116626
.. nonce: GsyczB
.. section: Core and Builtins
Ensure ``INSTRUMENTED_CALL_FUNCTION_EX`` always emits
:monitoring-event:`CALL`
..
.. date: 2024-03-11-00-45-39
.. gh-issue: 116554
.. nonce: gYumG5
.. section: Core and Builtins
``list.sort()`` now exploits more cases of partial ordering, particularly
those with long descending runs with sub-runs of equal values. Those are
recognized as single runs now (previously, each block of repeated values
caused a new run to be created).
..
.. date: 2024-03-07-16-12-39
.. gh-issue: 114099
.. nonce: ujdjn2
.. section: Core and Builtins
Added a Loader that can discover extension modules in an iOS-style
Frameworks folder.
..
.. date: 2024-02-25-14-17-25
.. gh-issue: 115775
.. nonce: CNbGbJ
.. section: Core and Builtins
Compiler populates the new ``__static_attributes__`` field on a class with
the names of attributes of this class which are accessed through self.X from
any function in its body.
..
.. date: 2024-02-24-03-39-09
.. gh-issue: 115776
.. nonce: THJXqg
.. section: Core and Builtins
The array of values, the ``PyDictValues`` struct is now embedded in the
object during allocation. This provides better performance in the common
case, and does not degrade as much when the object's ``__dict__`` is
materialized.
..
.. date: 2024-01-07-04-22-51
.. gh-issue: 108362
.. nonce: oB9Gcf
.. section: Core and Builtins
Implement an incremental cyclic garbage collector. By collecting the old
generation in increments, there is no need for a full heap scan. This can
hugely reduce maximum pause time for programs with large heaps.
Reduce the number of generations from three to two. The old generation is
split into two spaces, "visited" and "pending".
Collection happens in two steps:: * An increment is formed from the young
generation and a small part of the pending space. * This increment is
scanned and the survivors moved to the end of the visited space.
When the collecting space becomes empty, the two spaces are swapped.
..
.. date: 2023-10-14-00-05-17
.. gh-issue: 109870
.. nonce: oKpJ3P
.. section: Library
Dataclasses now calls :func:`exec` once per dataclass, instead of once per
method being added.  This can speed up dataclass creation by up to 20%.
..
.. date: 2022-10-05-09-33-48
.. gh-issue: 97901
.. nonce: BOLluU
.. section: Library
Mime type ``text/rtf`` is now supported by :mod:`mimetypes`.
..
.. bpo: 24612
.. date: 2021-09-04-22-33-01
.. nonce: SsTuUX
.. section: Core and Builtins
Improve the :exc:`SyntaxError` that happens when 'not' appears after an
operator. Patch by Pablo Galindo
..
.. date: 2024-04-08-20-26-15
.. gh-issue: 117648
.. nonce: NzVEa7
.. section: Library
Improve performance of :func:`os.path.join` and :func:`os.path.expanduser`.
..
.. date: 2024-04-06-16-42-34
.. gh-issue: 117584
.. nonce: hqk9Hn
.. section: Library
Raise :exc:`TypeError` for non-paths in :func:`posixpath.relpath
<os.path.relpath>`.
..
.. date: 2024-04-03-18-36-53
.. gh-issue: 117467
.. nonce: l6rWlj
.. section: Library
Preserve mailbox ownership when rewriting in :func:`mailbox.mbox.flush
<mailbox.Mailbox.flush>`.
Patch by Tony Mountifield.
..
.. date: 2024-04-02-20-30-12
.. gh-issue: 114848
.. nonce: YX4pEc
.. section: Library
Raise :exc:`FileNotFoundError` when ``getcwd()`` returns '(unreachable)',
which can happen on Linux >= 2.6.36 with glibc < 2.27.
..
.. date: 2024-04-02-13-13-46
.. gh-issue: 117459
.. nonce: jiIZmH
.. section: Library
:meth:`asyncio.asyncio.run_coroutine_threadsafe` now keeps the traceback of
:class:`CancelledError`, :class:`TimeoutError` and
:class:`InvalidStateError` which are raised in the coroutine.
..
.. date: 2024-03-29-21-43-19
.. gh-issue: 117381
.. nonce: fT0JFM
.. section: Library
Fix error message for :func:`ntpath.commonpath`.
..
.. date: 2024-03-29-15-58-01
.. gh-issue: 117337
.. nonce: 7w3Qwp
.. section: Library
Deprecate undocumented :func:`!glob.glob0` and :func:`!glob.glob1`
functions. Use :func:`glob.glob` and pass a directory to its *root_dir*
argument instead.
..
.. date: 2024-03-29-15-04-13
.. gh-issue: 117349
.. nonce: OB9kQQ
.. section: Library
Optimise several functions in :mod:`os.path`.
..
.. date: 2024-03-29-12-07-26
.. gh-issue: 117348
.. nonce: WjCYvK
.. section: Library
Refactored :meth:`configparser.RawConfigParser._read` to reduce cyclometric
complexity and improve comprehensibility.
..
.. date: 2024-03-28-19-13-20
.. gh-issue: 117335
.. nonce: d6uKJu
.. section: Library
Raise TypeError for non-sequences for :func:`ntpath.commonpath`.
..
.. date: 2024-03-28-17-55-22
.. gh-issue: 66449
.. nonce: 4jhuEV
.. section: Library
:class:`configparser.ConfigParser` now accepts unnamed sections before named
ones, if configured to do so.
..
.. date: 2024-03-28-13-54-20
.. gh-issue: 88014
.. nonce: zJz31I
.. section: Library
In documentation of :class:`gzip.GzipFile` in module gzip, explain data type
of optional constructor argument *mtime*, and recommend ``mtime = 0`` for
generating deterministic streams.
..
.. date: 2024-03-27-21-05-52
.. gh-issue: 117310
.. nonce: Bt2wox
.. section: Library
Fixed an unlikely early & extra ``Py_DECREF`` triggered crash in :mod:`ssl`
when creating a new ``_ssl._SSLContext`` if CPython was built implausibly
such that the default cipher list is empty **or** the SSL library it was
linked against reports a failure from its C ``SSL_CTX_set_cipher_list()``
API.
..
.. date: 2024-03-27-16-43-42
.. gh-issue: 117294
.. nonce: wbXNFv
.. section: Library
A ``DocTestCase`` now reports as skipped if all examples in the doctest are
skipped.
..
.. date: 2024-03-26-11-48-39
.. gh-issue: 98966
.. nonce: SayV9y
.. section: Library
In :mod:`subprocess`, raise a more informative message when
``stdout=STDOUT``.
..
.. date: 2024-03-25-21-15-56
.. gh-issue: 117225
.. nonce: oOaZXb
.. section: Library
doctest: only print "and X failed" when non-zero, don't pluralise "1 items".
Patch by Hugo van Kemenade.
..
.. date: 2024-03-25-00-20-16
.. gh-issue: 117205
.. nonce: yV7xGb
.. section: Library
Speed up :func:`compileall.compile_dir` by 20% when using multiprocessing by
increasing ``chunksize``.
..
.. date: 2024-03-23-14-26-18
.. gh-issue: 117178
.. nonce: vTisTG
.. section: Library
Fix regression in lazy loading of self-referential modules, introduced in
gh-114781.
..
.. date: 2024-03-23-13-40-13
.. gh-issue: 112383
.. nonce: XuHf3G
.. section: Library
Fix :mod:`dis` module's handling of ``ENTER_EXECUTOR`` instructions.
..
.. date: 2024-03-23-12-28-05
.. gh-issue: 117182
.. nonce: a0KANW
.. section: Library
Lazy-loading of modules that modify their own ``__class__`` no longer
reverts the ``__class__`` to :class:`types.ModuleType`.
..
.. date: 2024-03-21-17-07-38
.. gh-issue: 117084
.. nonce: w1mTpT
.. section: Library
Fix :mod:`zipfile` extraction for directory entries with the name containing
backslashes on Windows.
..
.. date: 2024-03-21-09-57-57
.. gh-issue: 117114
.. nonce: Qu-p55
.. section: Library
Make :func:`os.path.isdevdrive` available on all platforms. For those that
do not offer Dev Drives, it will always return ``False``.
..
.. date: 2024-03-21-07-27-36
.. gh-issue: 117110
.. nonce: 9K1InX
.. section: Library
Fix a bug that prevents subclasses of :class:`typing.Any` to be instantiated
with arguments. Patch by Chris Fu.
..
.. date: 2024-03-20-23-07-58
.. gh-issue: 109653
.. nonce: uu3lrX
.. section: Library
Deferred select imports in importlib.metadata and importlib.resources for a
14% speedup.
..
.. date: 2024-03-20-16-10-29
.. gh-issue: 70647
.. nonce: FpD6Ar
.. section: Library
Start the deprecation period for the current behavior of
:func:`datetime.datetime.strptime` and :func:`time.strptime` which always
fails to parse a date string with a :exc:`ValueError` involving a day of
month such as ``strptime("02-29", "%m-%d")`` when a year is **not**
specified and the date happen to be February 29th.  This should help avoid
users finding new bugs every four years due to a natural mistaken assumption
about the API when parsing partial date values.
..
.. date: 2024-03-19-19-42-25
.. gh-issue: 116987
.. nonce: ZVKUH1
.. section: Library
Fixed :func:`inspect.findsource` for class code objects.
..
.. date: 2024-03-19-14-35-57
.. gh-issue: 114099
.. nonce: siNSpK
.. section: Library
Modify standard library to allow for iOS platform differences.
..
.. date: 2024-03-19-11-08-26
.. gh-issue: 90872
.. nonce: ghys95
.. section: Library
On Windows, :meth:`subprocess.Popen.wait` no longer calls
``WaitForSingleObject()`` with a negative timeout: pass ``0`` ms if the
timeout is negative. Patch by Victor Stinner.
..
.. date: 2024-03-18-14-36-50
.. gh-issue: 116957
.. nonce: dTCs4f
.. section: Library
configparser: Don't leave ConfigParser values in an invalid state (stored as
a list instead of a str) after an earlier read raised DuplicateSectionError
or DuplicateOptionError.
..
.. date: 2024-03-17-18-12-39
.. gh-issue: 115538
.. nonce: PBiRQB
.. section: Library
:class:`!_io.WindowsConsoleIO` now emit a warning if a boolean value is
passed as a filedescriptor argument.
..
.. date: 2024-03-14-20-59-28
.. gh-issue: 90095
.. nonce: 7UaJ1U
.. section: Library
Ignore empty lines and comments in ``.pdbrc``
..
.. date: 2024-03-14-17-24-59
.. gh-issue: 106531
.. nonce: 9ehywi
.. section: Library
Refreshed zipfile._path from `zipp 3.18
<https://zipp.readthedocs.io/en/latest/history.html#v3-18-0>`_, providing
better compatibility for PyPy, better glob performance for deeply nested
zipfiles, and providing internal access to ``CompleteDirs.inject`` for use
in other tests (like importlib.resources).
..
.. date: 2024-03-14-17-21-25
.. gh-issue: 63207
.. nonce: LV16SL
.. section: Library
On Windows, :func:`time.time` now uses the
``GetSystemTimePreciseAsFileTime()`` clock to have a resolution better than
1 us, instead of the ``GetSystemTimeAsFileTime()`` clock which has a
resolution of 15.6 ms. Patch by Victor Stinner.
..
.. date: 2024-03-14-14-01-46
.. gh-issue: 116764
.. nonce: moB3Lc
.. section: Library
Restore support of ``None`` and other false values in :mod:`urllib.parse`
functions :func:`~urllib.parse.parse_qs` and
:func:`~urllib.parse.parse_qsl`. Also, they now raise a TypeError for
non-zero integers and non-empty sequences.
..
.. date: 2024-03-14-10-01-23
.. gh-issue: 116811
.. nonce: _h5iKP
.. section: Library
In ``PathFinder.invalidate_caches``, delegate to
``MetadataPathFinder.invalidate_caches``.
..
.. date: 2024-03-14-09-38-51
.. gh-issue: 116647
.. nonce: h0d_zj
.. section: Library
Fix recursive child in dataclasses
..
.. date: 2024-03-14-01-38-44
.. gh-issue: 113171
.. nonce: VFnObz
.. section: Library
Fixed various false positives and false negatives in
* :attr:`ipaddress.IPv4Address.is_private` (see these docs for details)
* :attr:`ipaddress.IPv4Address.is_global`
* :attr:`ipaddress.IPv6Address.is_private`
* :attr:`ipaddress.IPv6Address.is_global`
Also in the corresponding :class:`ipaddress.IPv4Network` and
:class:`ipaddress.IPv6Network` attributes.
..
.. date: 2024-03-13-15-45-54
.. gh-issue: 63283
.. nonce: OToJnG
.. section: Library
In :mod:`encodings.idna`, any capitalization of the ACE prefix
(``xn--``) is now acceptable. Patch by Pepijn de Vos and Zackery Spytz.
..
.. date: 2024-03-12-19-32-17
.. gh-issue: 71042
.. nonce: oI0Ron
.. section: Library
Add :func:`platform.android_ver`, which provides device and OS information
on Android.
..
.. date: 2024-03-12-17-53-14
.. gh-issue: 73468
.. nonce: z4ZzvJ
.. section: Library
Added new :func:`math.fma` function, wrapping C99's ``fma()`` operation:
fused multiply-add function. Patch by Mark Dickinson and Victor Stinner.
..
.. date: 2024-03-11-17-04-55
.. gh-issue: 116608
.. nonce: 30f58-
.. section: Library
The :mod:`importlib.resources` functions
:func:`~importlib.resources.is_resource`,
:func:`~importlib.resources.open_binary`,
:func:`~importlib.resources.open_text`,
:func:`~importlib.resources.path`,
:func:`~importlib.resources.read_binary`, and
:func:`~importlib.resources.read_text` are un-deprecated, and support
subdirectories via multiple positional arguments. The
:func:`~importlib.resources.contents` function also allows subdirectories,
but remains deprecated.
..
.. date: 2024-03-08-11-31-49
.. gh-issue: 116484
.. nonce: VMAsU7
.. section: Library
Change automatically generated :class:`tkinter.Checkbutton` widget names to
avoid collisions with automatically generated
:class:`tkinter.ttk.Checkbutton` widget names within the same parent widget.
..
.. date: 2024-03-07-11-10-27
.. gh-issue: 114314
.. nonce: iEhAMH
.. section: Library
In :mod:`ctypes`, ctype data is now stored in type objects directly rather
than in a dict subclass. This is an internal change that should not affect
usage.
..
.. date: 2024-03-06-18-30-37
.. gh-issue: 116401
.. nonce: 3Wcda2
.. section: Library
Fix blocking :func:`os.fwalk` and :func:`shutil.rmtree` on opening named
pipe.
..
.. date: 2024-03-05-19-56-29
.. gh-issue: 71052
.. nonce: PMDK--
.. section: Library
Implement :func:`ctypes.util.find_library` on Android.
..
.. date: 2024-03-01-20-23-57
.. gh-issue: 90535
.. nonce: wXm-jC
.. section: Library
Fix support of *interval* values > 1 in
:class:`logging.TimedRotatingFileHandler` for ``when='MIDNIGHT'`` and
``when='Wx'``.
..
.. date: 2024-02-26-10-06-50
.. gh-issue: 113308
.. nonce: MbvOFt
.. section: Library
Remove some internal protected parts from :mod:`uuid`:
``_has_uuid_generate_time_safe``, ``_netbios_getnode``,
``_ipconfig_getnode``, and ``_load_system_functions``. They were unused.
..
.. date: 2024-02-18-09-50-31
.. gh-issue: 115627
.. nonce: HGchj0
.. section: Library
Fix the :mod:`ssl` module error handling of connection terminate by peer. It
now throws an OSError with the appropriate error code instead of an
EOFError.
..
.. date: 2024-02-01-08-09-20
.. gh-issue: 114847
.. nonce: -JrWrR
.. section: Library
Speed up :func:`os.path.realpath` on non-Windows platforms.
..
.. date: 2024-02-01-03-09-38
.. gh-issue: 114271
.. nonce: raCkt5
.. section: Library
Fix a race in ``threading.Thread.join()``.
``threading._MainThread`` now always represents the main thread of the main
interpreter.
``PyThreadState.on_delete`` and ``PyThreadState.on_delete_data`` have been
removed.
..
.. date: 2024-01-22-15-50-58
.. gh-issue: 113538
.. nonce: v2wrwg
.. section: Library
Add :meth:`asyncio.Server.close_clients` and
:meth:`asyncio.Server.abort_clients` methods which allow to more forcefully
close an asyncio server.
..
.. date: 2024-01-02-22-47-12
.. gh-issue: 85287
.. nonce: ZC5DLj
.. section: Library
Changes Unicode codecs to return UnicodeEncodeError or UnicodeDecodeError,
rather than just UnicodeError.
..
.. date: 2023-12-28-22-52-45
.. gh-issue: 113548
.. nonce: j6TJ7O
.. section: Library
:mod:`pdb` now allows CLI arguments to ``pdb -m``.
..
.. date: 2023-12-11-00-51-51
.. gh-issue: 112948
.. nonce: k-OKp5
.. section: Library
Make completion of :mod:`pdb` similar to Python REPL
..
.. date: 2023-06-16-19-17-06
.. gh-issue: 105866
.. nonce: 0NBveV
.. section: Library
Fixed ``_get_slots`` bug which caused error when defining dataclasses with
slots and a weakref_slot.
..
.. date: 2023-05-06-05-00-42
.. gh-issue: 96471
.. nonce: S3X5I-
.. section: Library
Add :py:class:`asyncio.Queue` termination with
:py:meth:`~asyncio.Queue.shutdown` method.
..
.. date: 2022-06-22-14-45-32
.. gh-issue: 89739
.. nonce: CqZcRL
.. section: Library
The :mod:`zipimport` module can now read ZIP64 files.
..
.. bpo: 33533
.. date: 2020-10-02-17-35-19
.. nonce: GLIhM5
.. section: Library
:func:`asyncio.as_completed` now returns an object that is both an
asynchronous iterator and plain iterator. The new asynchronous iteration
pattern allows for easier correlation between prior tasks and their
completed results. This is a closer match to
:func:`concurrent.futures.as_completed`'s iteration pattern. Patch by Justin
Arthur.
..
.. bpo: 27578
.. date: 2020-06-11-16-20-33
.. nonce: CIA-fu
.. section: Library
:func:`inspect.getsource` (and related functions) work with empty module
files, returning ``'\n'`` (or reasonable equivalent) instead of raising
``OSError``. Patch by Kernc.
..
.. bpo: 37141
.. date: 2019-09-26-17-52-52
.. nonce: onYY2-
.. section: Library
Accept an iterable of separators in :meth:`asyncio.StreamReader.readuntil`,
stopping when one of them is encountered.
..
.. date: 2019-08-27-01-03-26
.. gh-issue: 66543
.. nonce: _TRpYr
.. section: Library
Make :func:`mimetypes.guess_type` properly parsing of URLs with only a host
name, URLs containing fragment or query, and filenames with only a UNC
sharepoint on Windows. Based on patch by Dong-hee Na.
..
.. bpo: 15010
.. date: 2019-08-12-19-08-06
.. nonce: 3bY2CF
.. section: Library
:meth:`unittest.TestLoader.discover` now saves the original value of
``unittest.TestLoader._top_level_dir`` and restores it at the end of the
call.
..
.. date: 2024-03-20-15-12-37
.. gh-issue: 115977
.. nonce: IMLi6K
.. section: Documentation
Remove compatibility references to Emscripten.
..
.. date: 2024-03-20-12-41-47
.. gh-issue: 114099
.. nonce: ad_Ck9
.. section: Documentation
Add an iOS platform guide, and flag modules not available on iOS.
..
.. date: 2022-04-15-13-15-23
.. gh-issue: 91565
.. nonce: OznXwC
.. section: Documentation
Changes to documentation files and config outputs to reflect the new
location for reporting bugs - i.e. GitHub rather than bugs.python.org.
..
.. date: 2024-03-25-21-31-49
.. gh-issue: 83434
.. nonce: U7Z8cY
.. section: Tests
Disable JUnit XML output (``--junit-xml=FILE`` command line option) in
regrtest when hunting for reference leaks (``-R`` option). Patch by Victor
Stinner.
..
.. date: 2024-03-24-23-49-25
.. gh-issue: 117187
.. nonce: eMLT5n
.. section: Tests
Fix XML tests for vanilla Expat <2.6.0.
..
.. date: 2024-03-21-11-32-29
.. gh-issue: 116333
.. nonce: F-9Ram
.. section: Tests
Tests of TLS related things (error codes, etc) were updated to be more
lenient about specific error message strings and behaviors as seen in the
BoringSSL and AWS-LC forks of OpenSSL.
..
.. date: 2024-03-20-14-19-32
.. gh-issue: 117089
.. nonce: WwR1Z1
.. section: Tests
Consolidated tests for importlib.metadata in their own ``metadata`` package.
..
.. date: 2024-03-13-12-06-49
.. gh-issue: 115979
.. nonce: zsNpQD
.. section: Tests
Update test_importlib so that it passes under WASI SDK 21.
..
.. date: 2024-03-11-23-20-28
.. gh-issue: 112536
.. nonce: Qv1RrX
.. section: Tests
Add --tsan to test.regrtest for running TSAN tests in reasonable execution
times. Patch by Donghee Na.
..
.. date: 2024-03-06-11-00-36
.. gh-issue: 116307
.. nonce: Uij0t_
.. section: Tests
Added import helper ``isolated_modules`` as ``CleanImport`` does not remove
modules imported during the context. Use it in importlib.resources tests to
avoid leaving ``mod`` around to impede importlib.metadata tests.
..
.. date: 2024-03-13-16-16-43
.. gh-issue: 114736
.. nonce: ZhmauG
.. section: Build
Have WASI builds use WASI SDK 21.
..
.. date: 2024-03-08-17-05-15
.. gh-issue: 115983
.. nonce: ZQqk0Q
.. section: Build
Skip building test modules that must be built as shared under WASI.
..
.. date: 2024-03-06-17-26-55
.. gh-issue: 71052
.. nonce: vLbu9u
.. section: Build
Add Android build script and instructions.
..
.. date: 2024-03-28-22-12-00
.. gh-issue: 117267
.. nonce: K_tki1
.. section: Windows
Ensure ``DirEntry.stat().st_ctime`` behaves consistently with
:func:`os.stat` during the deprecation period of ``st_ctime`` by containing
the same value as ``st_birthtime``. After the deprecation period,
``st_ctime`` will be the metadata change time (or unavailable through
``DirEntry``), and only ``st_birthtime`` will contain the creation time.
..
.. date: 2024-03-14-20-46-23
.. gh-issue: 116195
.. nonce: Cu_rYs
.. section: Windows
Improves performance of :func:`os.getppid` by using an alternate system API
when available. Contributed by vxiiduu.
..
.. date: 2024-03-14-09-14-21
.. gh-issue: 88494
.. nonce: Bwfmp7
.. section: Windows
On Windows, :func:`time.monotonic` now uses the
``QueryPerformanceCounter()`` clock to have a resolution better than 1 us,
instead of the ``GetTickCount64()`` clock which has a resolution of 15.6 ms.
Patch by Victor Stinner.
..
.. date: 2024-03-14-01-58-22
.. gh-issue: 116773
.. nonce: H2UldY
.. section: Windows
Fix instances of ``<_overlapped.Overlapped object at 0xXXX> still has
pending operation at deallocation, the process may crash``.
..
.. date: 2024-02-24-23-03-43
.. gh-issue: 91227
.. nonce: sL4zWC
.. section: Windows
Fix the asyncio ProactorEventLoop implementation so that sending a datagram
to an address that is not listening does not prevent receiving any more
datagrams.
..
.. date: 2024-02-08-14-48-15
.. gh-issue: 115119
.. nonce: qMt32O
.. section: Windows
Switched from vendored ``libmpdecimal`` code to a separately-hosted external
package in the ``cpython-source-deps`` repository when building the
``_decimal`` module.
..
.. date: 2024-04-08-18-53-33
.. gh-issue: 117642
.. nonce: _-tYH_
.. section: C API
Fix :pep:`737` implementation for ``%#T`` and ``%#N``.
..
.. date: 2024-03-22-19-29-24
.. gh-issue: 87193
.. nonce: u7O-jY
.. section: C API
:c:func:`_PyBytes_Resize` can now be called for bytes objects with reference
count > 1, including 1-byte bytes objects. It creates a new bytes object and
destroys the old one if it has reference count > 1.
..
.. date: 2024-03-20-13-13-22
.. gh-issue: 117021
.. nonce: 0Q5jBx
.. section: C API
Fix integer overflow in :c:func:`PyLong_AsPid` on non-Windows 64-bit
platforms.
..
.. date: 2024-03-19-09-49-04
.. gh-issue: 115756
.. nonce: 4Ls_Tl
.. section: C API
:c:func:`!PyCode_GetFirstFree` is an ustable API now and has been renamed to
:c:func:`PyUnstable_Code_GetFirstFree`. (Contributed by Bogdan Romanyuk in
:gh:`115781`)
..
.. date: 2024-03-18-10-58-47
.. gh-issue: 116869
.. nonce: lN0GBl
.. section: C API
Add ``test_cext`` test: build a C extension to check if the Python C API
emits C compiler warnings. Patch by Victor Stinner.
..
.. date: 2024-03-18-09-58-46
.. gh-issue: 116869
.. nonce: LFDVKM
.. section: C API
Make the C API compatible with ``-Werror=declaration-after-statement``
compiler flag again. Patch by Victor Stinner.
..
.. date: 2024-03-17-22-42-21
.. gh-issue: 116936
.. nonce: tNrzfm
.. section: C API
Add :c:func:`PyType_GetModuleByDef` to the limited C API. Patch by Victor
Stinner.
..
.. date: 2024-03-16-12-21-00
.. gh-issue: 116809
.. nonce: JL786L
.. section: C API
Restore removed private ``_PyErr_ChainExceptions1()`` function. Patch by
Victor Stinner.
..
.. date: 2024-03-15-23-57-33
.. gh-issue: 115754
.. nonce: zLdv82
.. section: C API
In the limited C API version 3.13, getting ``Py_None``, ``Py_False``,
``Py_True``, ``Py_Ellipsis`` and ``Py_NotImplemented`` singletons is now
implemented as function calls at the stable ABI level to hide implementation
details. Getting these constants still return borrowed references. Patch by
Victor Stinner.
..
.. date: 2024-03-15-23-55-24
.. gh-issue: 115754
.. nonce: xnzc__
.. section: C API
Add :c:func:`Py_GetConstant` and :c:func:`Py_GetConstantBorrowed` functions
to get constants. For example, ``Py_GetConstant(Py_CONSTANT_ZERO)`` returns
a :term:`strong reference` to the constant zero. Patch by Victor Stinner.
..
.. date: 2024-03-14-22-30-07
.. gh-issue: 111696
.. nonce: 76UMKi
.. section: C API
Add support for ``%T``, ``%T#``, ``%N`` and ``%N#`` formats to
:c:func:`PyUnicode_FromFormat`: format the fully qualified name of an object
type and of a type: call :c:func:`PyType_GetModuleName`. See :pep:`737` for
more information. Patch by Victor Stinner.
..
.. date: 2024-03-14-18-00-32
.. gh-issue: 111696
.. nonce: L6oIPq
.. section: C API
Add :c:func:`PyType_GetModuleName` function to get the type's module name.
Equivalent to getting the ``type.__module__`` attribute. Patch by Eric Snow
and Victor Stinner.
..
.. date: 2024-03-14-15-17-11
.. gh-issue: 111696
.. nonce: YmnvAi
.. section: C API
Add :c:func:`PyType_GetFullyQualifiedName` function to get the type's fully
qualified name. Equivalent to ``f"{type.__module__}.{type.__qualname__}"``,
or ``type.__qualname__`` if ``type.__module__`` is not a string or is equal
to ``"builtins"``. Patch by Victor Stinner.
..
.. date: 2024-03-14-10-33-58
.. gh-issue: 85283
.. nonce: LOgmdU
.. section: C API
The ``fcntl``, ``grp``, ``pwd``, ``termios``, ``_statistics`` and
``_testconsole`` C extensions are now built with the :ref:`limited C API
<limited-c-api>`. Patch by Victor Stinner.
..
.. date: 2024-02-28-15-50-01
.. gh-issue: 111140
.. nonce: mpwcUg
.. section: C API
Add additional flags to :c:func:`PyLong_AsNativeBytes` and
:c:func:`PyLong_FromNativeBytes` to allow the caller to determine how to
handle edge cases around values that fill the entire buffer.
..
.. date: 2023-12-12-19-48-31
.. gh-issue: 113024
.. nonce: rXcQs7
.. section: C API
Add :c:func:`PyObject_GenericHash` function.

.. bpo: 39427
.. date: 2020-01-22-22-28-04
.. nonce: LiO-Eo
.. release date: 2020-01-24
.. section: Core and Builtins
Document all possibilities for the ``-X`` options in the command line help
section. Patch by Pablo Galindo.
..
.. bpo: 39421
.. date: 2020-01-22-15-53-37
.. nonce: O3nG7u
.. section: Core and Builtins
Fix possible crashes when operating with the functions in the :mod:`heapq`
module and custom comparison operators.
..
.. bpo: 39386
.. date: 2020-01-20-21-40-57
.. nonce: ULqD8t
.. section: Core and Builtins
Prevent double awaiting of async iterator.
..
.. bpo: 17005
.. date: 2020-01-17-00-00-58
.. nonce: nTSxsy
.. section: Core and Builtins
Add :class:`functools.TopologicalSorter` to the :mod:`functools` module to
offers functionality to perform topological sorting of graphs. Patch by
Pablo Galindo, Tim Peters and Larry Hastings.
..
.. bpo: 39320
.. date: 2020-01-15-15-33-44
.. nonce: b4hnJW
.. section: Core and Builtins
Replace four complex bytecodes for building sequences with three simpler
ones.
The following four bytecodes have been removed:
* BUILD_LIST_UNPACK
* BUILD_TUPLE_UNPACK
* BUILD_SET_UNPACK
* BUILD_TUPLE_UNPACK_WITH_CALL
The following three bytecodes have been added:
* LIST_TO_TUPLE
* LIST_EXTEND
* SET_UPDATE
..
.. bpo: 39336
.. date: 2020-01-15-01-39-29
.. nonce: nJ7W9I
.. section: Core and Builtins
Import loaders which publish immutable module objects can now publish
immutable packages in addition to individual modules.
..
.. bpo: 39322
.. date: 2020-01-13-15-18-13
.. nonce: aAs-1T
.. section: Core and Builtins
Added a new function :func:`gc.is_finalized` to check if an object has been
finalized by the garbage collector. Patch by Pablo Galindo.
..
.. bpo: 39048
.. date: 2020-01-13-14-45-22
.. nonce: iPsj81
.. section: Core and Builtins
Improve the displayed error message when incorrect types are passed to
``async with`` statements by looking up the :meth:`__aenter__` special
method before the :meth:`__aexit__` special method when entering an
asynchronous context manager. Patch by Géry Ogam.
..
.. bpo: 39235
.. date: 2020-01-09-10-01-18
.. nonce: RYwjoc
.. section: Core and Builtins
Fix AST end location for lone generator expression in function call, e.g.
f(i for i in a).
..
.. bpo: 39209
.. date: 2020-01-06-10-29-16
.. nonce: QHAONe
.. section: Core and Builtins
Correctly handle multi-line tokens in interactive mode. Patch by Pablo
Galindo.
..
.. bpo: 1635741
.. date: 2020-01-05-13-40-08
.. nonce: QRTJVC
.. section: Core and Builtins
Port _json extension module to multiphase initialization (:pep:`489`).
..
.. bpo: 39216
.. date: 2020-01-05-06-55-52
.. nonce: 74jLh9
.. section: Core and Builtins
Fix constant folding optimization for positional only arguments - by Anthony
Sottile.
..
.. bpo: 39215
.. date: 2020-01-04-17-25-34
.. nonce: xiqiIz
.. section: Core and Builtins
Fix ``SystemError`` when nested function has annotation on positional-only
argument - by Anthony Sottile.
..
.. bpo: 39200
.. date: 2020-01-04-01-14-32
.. nonce: 8Z9DYp
.. section: Core and Builtins
Correct the error message when calling the :func:`min` or :func:`max` with
no arguments. Patch by Donghee Na.
..
.. bpo: 39200
.. date: 2020-01-03-14-50-14
.. nonce: Ip2_iI
.. section: Core and Builtins
Correct the error message when trying to construct :class:`range` objects
with no arguments. Patch by Pablo Galindo.
..
.. bpo: 39166
.. date: 2020-01-02-22-22-03
.. nonce: Qt-UeD
.. section: Core and Builtins
Fix incorrect line execution reporting in trace functions when tracing the
last iteration of asynchronous for loops. Patch by Pablo Galindo.
..
.. bpo: 39114
.. date: 2019-12-31-18-25-45
.. nonce: WG9alt
.. section: Core and Builtins
Fix incorrect line execution reporting in trace functions when tracing
exception handlers with name binding. Patch by Pablo Galindo.
..
.. bpo: 39156
.. date: 2019-12-30-10-53-59
.. nonce: veT-CB
.. section: Core and Builtins
Split the COMPARE_OP bytecode instruction into four distinct instructions.
*  COMPARE_OP for rich comparisons
*  IS_OP for 'is' and 'is not' tests
*  CONTAINS_OP for 'in' and 'is not' tests
*  JUMP_IF_NOT_EXC_MATCH for checking exceptions in 'try-except' statements.
This improves the clarity of the interpreter and should provide a modest
speedup.
..
.. bpo: 38588
.. date: 2019-12-29-19-13-54
.. nonce: pgXnNS
.. section: Core and Builtins
Fix possible crashes in dict and list when calling
:c:func:`PyObject_RichCompareBool`.
..
.. bpo: 13601
.. date: 2019-12-17-22-32-11
.. nonce: vNP4LC
.. section: Core and Builtins
By default, ``sys.stderr`` is line-buffered now, even if ``stderr`` is
redirected to a file. You can still make ``sys.stderr`` unbuffered by
passing the :option:`-u` command-line option or setting the
:envvar:`PYTHONUNBUFFERED` environment variable.
(Contributed by Jendrik Seipp in bpo-13601.)
..
.. bpo: 38610
.. date: 2019-10-31-14-30-39
.. nonce: fHdVMS
.. section: Core and Builtins
Fix possible crashes in several list methods by holding strong references to
list elements when calling :c:func:`PyObject_RichCompareBool`.
..
.. bpo: 32021
.. date: 2019-03-11-13-30-40
.. nonce: dpbtkP
.. section: Core and Builtins
Include brotli .br encoding in mimetypes encodings_map
..
.. bpo: 39430
.. date: 2020-01-24-11-05-21
.. nonce: I0UQzM
.. section: Library
Fixed race condition in lazy imports in :mod:`tarfile`.
..
.. bpo: 39413
.. date: 2020-01-24-10-10-25
.. nonce: 7XYDM8
.. section: Library
The :func:`os.unsetenv` function is now also available on Windows.
..
.. bpo: 39390
.. date: 2020-01-23-21-34-29
.. nonce: D2tSXk
.. section: Library
Fixed a regression with the ``ignore`` callback of :func:`shutil.copytree`.
The argument types are now ``str`` and ``List[str]`` again.
..
.. bpo: 39395
.. date: 2020-01-23-03-05-41
.. nonce: 4dda42
.. section: Library
The :func:`os.putenv` and :func:`os.unsetenv` functions are now always
available.
..
.. bpo: 39406
.. date: 2020-01-22-21-18-58
.. nonce: HMpe8x
.. section: Library
If ``setenv()`` C function is available, :func:`os.putenv` is now
implemented with ``setenv()`` instead of ``putenv()``, so Python doesn't
have to handle the environment variable memory.
..
.. bpo: 39396
.. date: 2020-01-21-09-00-42
.. nonce: 6UXQXE
.. section: Library
Fix ``math.nextafter(-0.0, +0.0)`` on AIX 7.1.
..
.. bpo: 29435
.. date: 2020-01-20-18-48-00
.. nonce: qqJ2Ax
.. section: Library
Allow :func:`tarfile.is_tarfile` to be used with file and file-like objects,
like :func:`zipfile.is_zipfile`. Patch by William Woodruff.
..
.. bpo: 39377
.. date: 2020-01-20-13-00-35
.. nonce: QSFdaU
.. section: Library
Removed ``encoding`` option from :func:`json.loads`.  It has been deprecated
since Python 3.1.
..
.. bpo: 39389
.. date: 2020-01-20-00-56-01
.. nonce: fEirIS
.. section: Library
Write accurate compression level metadata in :mod:`gzip` archives, rather
than always signaling maximum compression.
..
.. bpo: 39366
.. date: 2020-01-17-18-14-51
.. nonce: Cv3NQS
.. section: Library
The previously deprecated ``xpath()`` and ``xgtitle()`` methods of
:class:`!nntplib.NNTP` have been removed.
..
.. bpo: 39357
.. date: 2020-01-16-11-24-00
.. nonce: bCwx-h
.. section: Library
Remove the *buffering* parameter of :class:`bz2.BZ2File`. Since Python 3.0,
it was ignored and using it was emitting :exc:`DeprecationWarning`. Pass an
open file object, to control how the file is opened. The *compresslevel*
parameter becomes keyword-only.
..
.. bpo: 39353
.. date: 2020-01-16-10-21-48
.. nonce: ntp7Ql
.. section: Library
Deprecate binhex4 and hexbin4 standards. Deprecate the :mod:`binhex` module
and the following :mod:`binascii` functions: :func:`~binascii.b2a_hqx`,
:func:`~binascii.a2b_hqx`, :func:`~binascii.rlecode_hqx`,
:func:`~binascii.rledecode_hqx`, :func:`~binascii.crc_hqx`.
..
.. bpo: 39351
.. date: 2020-01-16-09-27-28
.. nonce: a-FQdv
.. section: Library
Remove ``base64.encodestring()`` and ``base64.decodestring()``, aliases
deprecated since Python 3.1: use :func:`base64.encodebytes` and
:func:`base64.decodebytes` instead.
..
.. bpo: 39350
.. date: 2020-01-16-09-15-40
.. nonce: ZQx0uY
.. section: Library
Remove ``fractions.gcd()`` function, deprecated since Python 3.5
(:issue:`22486`): use :func:`math.gcd` instead.
..
.. bpo: 39329
.. date: 2020-01-14-22-16-07
.. nonce: 6OKGBn
.. section: Library
:class:`~smtplib.LMTP` constructor now has an optional *timeout* parameter.
Patch by Donghee Na.
..
.. bpo: 39313
.. date: 2020-01-12-18-17-00
.. nonce: DCTsnm
.. section: Library
Add a new ``exec_function`` option (*--exec-function* in the CLI) to
``RefactoringTool`` for making ``exec`` a function. Patch by Batuhan
Taskaya.
..
.. bpo: 39259
.. date: 2020-01-12-17-19-40
.. nonce: iax06r
.. section: Library
:class:`~ftplib.FTP_TLS` and :class:`~ftplib.FTP_TLS` now raise a
:class:`ValueError` if the given timeout for their constructor is zero to
prevent the creation of a non-blocking socket. Patch by Donghee Na.
..
.. bpo: 39259
.. date: 2020-01-12-16-34-28
.. nonce: J_yBVq
.. section: Library
:class:`~smtplib.SMTP` and :class:`~smtplib.SMTP_SSL` now raise a
:class:`ValueError` if the given timeout for their constructor is zero to
prevent the creation of a non-blocking socket. Patch by Donghee Na.
..
.. bpo: 39310
.. date: 2020-01-12-13-34-42
.. nonce: YMRdcj
.. section: Library
Add :func:`math.ulp`: return the value of the least significant bit of a
float.
..
.. bpo: 39297
.. date: 2020-01-11-01-15-37
.. nonce: y98Z6Q
.. section: Library
Improved performance of importlib.metadata distribution discovery and
resilients to inaccessible sys.path entries (importlib_metadata v1.4.0).
..
.. bpo: 39259
.. date: 2020-01-11-00-32-45
.. nonce: _S5VjC
.. section: Library
:class:`!NNTP` and :class:`!NNTP_SSL` now raise a
:class:`ValueError` if the given timeout for their constructor is zero to
prevent the creation of a non-blocking socket. Patch by Donghee Na.
..
.. bpo: 38901
.. date: 2020-01-10-22-30-48
.. nonce: OdVIIb
.. section: Library
When you specify prompt='.' or equivalently python -m venv --prompt . ...
the basename of the current directory is used to set the created venv's
prompt when it's activated.
..
.. bpo: 39288
.. date: 2020-01-10-16-52-09
.. nonce: IB-aQX
.. section: Library
Add :func:`math.nextafter`: return the next floating-point value after *x*
towards *y*.
..
.. bpo: 39259
.. date: 2020-01-09-10-58-58
.. nonce: RmDgCC
.. section: Library
:class:`~poplib.POP3` and :class:`~poplib.POP3_SSL` now raise a
:class:`ValueError` if the given timeout for their constructor is zero to
prevent the creation of a non-blocking socket. Patch by Donghee Na.
..
.. bpo: 39242
.. date: 2020-01-08-23-25-27
.. nonce: bnL65N
.. section: Library
Updated the Gmane domain from news.gmane.org to news.gmane.io which is used
for examples of :class:`!NNTP` news reader server and nntplib tests.
..
.. bpo: 35292
.. date: 2020-01-08-14-39-19
.. nonce: ihRT1z
.. section: Library
Proxy the ``SimpleHTTPRequestHandler.guess_type`` to ``mimetypes.guess_type`` so
the ``mimetypes.init`` is called lazily to avoid unnecessary costs when
:mod:`http.server` module is imported.
..
.. bpo: 39239
.. date: 2020-01-07-01-02-44
.. nonce: r7vecs
.. section: Library
The :meth:`select.epoll.unregister` method no longer ignores the
:data:`~errno.EBADF` error.
..
.. bpo: 38907
.. date: 2020-01-06-02-14-38
.. nonce: F1RkCR
.. section: Library
In http.server script, restore binding to IPv4 on Windows.
..
.. bpo: 39152
.. date: 2020-01-03-18-02-50
.. nonce: JgPjCC
.. section: Library
Fix ttk.Scale.configure([name]) to return configuration tuple for name or
all options.  Giovanni Lombardo contributed part of the patch.
..
.. bpo: 39198
.. date: 2020-01-02-20-21-03
.. nonce: nzwGyG
.. section: Library
If an exception were to be thrown in ``Logger.isEnabledFor`` (say, by asyncio
timeouts or stopit) , the ``logging`` global lock may not be released
appropriately, resulting in deadlock.  This change wraps that block of code
with ``try...finally`` to ensure the lock is released.
..
.. bpo: 39191
.. date: 2020-01-02-17-28-03
.. nonce: ur_scy
.. section: Library
Perform a check for running loop before starting a new task in
``loop.run_until_complete()`` to fail fast; it prevents the side effect of
new task spawning before exception raising.
..
.. bpo: 38871
.. date: 2020-01-01-18-44-52
.. nonce: 3EEOLg
.. section: Library
Correctly parenthesize filter-based statements that contain lambda
expressions in :mod:`!lib2to3`. Patch by Donghee Na.
..
.. bpo: 39142
.. date: 2019-12-31-19-27-23
.. nonce: oqU5iD
.. section: Library
A change was made to logging.config.dictConfig to avoid converting instances
of named tuples to ConvertingTuple. It's assumed that named tuples are too
specialised to be treated like ordinary tuples; if a user of named tuples
requires ConvertingTuple functionality, they will have to implement that
themselves in their named tuple class.
..
.. bpo: 39158
.. date: 2019-12-29-15-44-38
.. nonce: cxVoOR
.. section: Library
ast.literal_eval() now supports empty sets.
..
.. bpo: 39129
.. date: 2019-12-24-10-43-13
.. nonce: jVx5rW
.. section: Library
Fix import path for ``asyncio.TimeoutError``
..
.. bpo: 39057
.. date: 2019-12-15-21-47-54
.. nonce: FOxn-w
.. section: Library
:func:`urllib.request.proxy_bypass_environment` now ignores leading dots and
no longer ignores a trailing newline.
..
.. bpo: 39056
.. date: 2019-12-15-21-05-16
.. nonce: nEfUM9
.. section: Library
Fixed handling invalid warning category in the -W option.  No longer import
the re module if it is not needed.
..
.. bpo: 39055
.. date: 2019-12-15-19-23-23
.. nonce: FmN3un
.. section: Library
:func:`base64.b64decode` with ``validate=True`` raises now a binascii.Error
if the input ends with a single ``\n``.
..
.. bpo: 21600
.. date: 2019-12-14-14-38-40
.. nonce: kC4Cgh
.. section: Library
Fix :func:`mock.patch.stopall` to stop active patches that were created with
:func:`mock.patch.dict`.
..
.. bpo: 39019
.. date: 2019-12-10-21-11-05
.. nonce: YIlgZ7
.. section: Library
Implement dummy ``__class_getitem__`` for
:class:`tempfile.SpooledTemporaryFile`.
..
.. bpo: 39019
.. date: 2019-12-10-21-03-34
.. nonce: i8RpMZ
.. section: Library
Implement dummy ``__class_getitem__`` for ``subprocess.Popen``,
``subprocess.CompletedProcess``
..
.. bpo: 38914
.. date: 2019-11-26-23-21-56
.. nonce: 8l-g-T
.. section: Library
Adjusted the wording of the warning issued by distutils' ``check`` command
when the ``author`` and ``maintainer`` fields are supplied but no
corresponding e-mail field (``author_email`` or ``maintainer_email``) is
found. The wording now reflects the fact that these fields are suggested,
but not required. Patch by Juergen Gmach.
..
.. bpo: 38878
.. date: 2019-11-22-12-08-52
.. nonce: EJ0cFf
.. section: Library
Fixed __subclasshook__ of :class:`os.PathLike` to return a correct result
upon inheritance. Patch by Bar Harel.
..
.. bpo: 38615
.. date: 2019-11-17-17-32-35
.. nonce: OVyaNX
.. section: Library
:class:`~imaplib.IMAP4` and :class:`~imaplib.IMAP4_SSL` now have an optional
*timeout* parameter for their constructors. Also, the
:meth:`~imaplib.IMAP4.open` method now has an optional *timeout* parameter
with this change. The overridden methods of :class:`~imaplib.IMAP4_SSL` and
:class:`~imaplib.IMAP4_stream` were applied to this change. Patch by
Donghee Na.
..
.. bpo: 35182
.. date: 2019-10-31-19-23-25
.. nonce: hzeNl9
.. section: Library
Fixed :func:`Popen.communicate` subsequent call crash when the child process
has already closed any piped standard stream, but still continues to be
running. Patch by Andriy Maletsky.
..
.. bpo: 38630
.. date: 2019-10-29-12-21-10
.. nonce: Dv6Xrm
.. section: Library
On Unix, :meth:`subprocess.Popen.send_signal` now polls the process status.
Polling reduces the risk of sending a signal to the wrong process if the
process completed, the :attr:`subprocess.Popen.returncode` attribute is
still ``None``, and the pid has been reassigned (recycled) to a new
different process.
..
.. bpo: 38536
.. date: 2019-10-21-20-24-51
.. nonce: beZ0Sk
.. section: Library
Removes trailing space in formatted currency with ``international=True`` and a
locale with symbol following value. E.g. ``locale.currency(12.34,
international=True)`` returned ``'12,34 EUR '`` instead of ``'12,34 EUR'``.
..
.. bpo: 38473
.. date: 2019-10-14-21-14-55
.. nonce: uXpVld
.. section: Library
Use signature from inner mock for autospecced methods attached with
:func:`unittest.mock.attach_mock`. Patch by Karthikeyan Singaravelan.
..
.. bpo: 38361
.. date: 2019-10-04-09-49-56
.. nonce: LM4u4T
.. section: Library
Fixed an issue where ``ident`` could include a leading path separator when
:func:`syslog.openlog` was called without arguments.
..
.. bpo: 38293
.. date: 2019-09-29-08-17-03
.. nonce: wls5s3
.. section: Library
Add :func:`copy.copy` and :func:`copy.deepcopy` support to :func:`property`
objects.
..
.. bpo: 37958
.. date: 2019-08-27-03-57-25
.. nonce: lRORI3
.. section: Library
Added the pstats.Stats.get_profile_dict() method to return the profile data
as a StatsProfile instance.
..
.. bpo: 28367
.. date: 2019-05-06-22-38-47
.. nonce: 2AKen5
.. section: Library
Termios magic constants for the following baud rates:   - B500000   -
B576000   - B921600   - B1000000   - B1152000   - B1500000   - B2000000   -
B2500000   - B3000000   - B3500000   - B4000000 Patch by Andrey Smirnov
..
.. bpo: 39381
.. date: 2020-01-18-15-37-56
.. nonce: wTWe8d
.. section: Documentation
Mention in docs that :func:`asyncio.get_event_loop` implicitly creates new
event loop only if called from the main thread.
..
.. bpo: 38918
.. date: 2019-12-15-22-04-41
.. nonce: 8JnDTS
.. section: Documentation
Add an entry for ``__module__`` in the "function" & "method" sections of the
:mod:`inspect` docs' :ref:`inspect-types` table.
..
.. bpo: 3530
.. date: 2019-11-17-11-53-10
.. nonce: 8zFUMc
.. section: Documentation
In the :mod:`ast` module documentation, fix a misleading ``NodeTransformer``
example and add advice on when to use the ``fix_missing_locations``
function.
..
.. bpo: 39395
.. date: 2020-01-23-03-05-13
.. nonce: RoArIZ
.. section: Build
On non-Windows platforms, the :c:func:`setenv` and :c:func:`unsetenv`
functions are now required to build Python.
..
.. bpo: 39160
.. date: 2019-12-30-03-54-24
.. nonce: aBmj13
.. section: Build
Updated the documentation in ``./configure --help`` to show default values,
reference documentation where required and add additional explanation where
needed.
..
.. bpo: 39144
.. date: 2019-12-27-22-18-26
.. nonce: dwHMlR
.. section: Build
The ctags and etags build targets both include Modules/_ctypes and Python
standard library source files.
..
.. bpo: 39050
.. date: 2020-01-22-22-28-06
.. nonce: zkn0FO
.. section: IDLE
Make IDLE Settings dialog Help button work again.
..
.. bpo: 34118
.. date: 2019-12-30-16-44-07
.. nonce: FaNW0a
.. section: IDLE
Tag memoryview, range, and tuple as classes, the same as list, etcetera, in
the library manual built-in functions list.
..
.. bpo: 32989
.. date: 2018-03-03-12-56-26
.. nonce: FVhmhH
.. section: IDLE
Add tests for editor newline_and_indent_event method. Remove dead code from
pyparse find_good_parse_start method.
..
.. bpo: 39372
.. date: 2020-01-17-19-25-48
.. nonce: hGJMY6
.. section: C API
Clean header files of interfaces defined but with no implementation. The
public API symbols being removed are:
``_PyBytes_InsertThousandsGroupingLocale``,
``_PyBytes_InsertThousandsGrouping``, ``_Py_InitializeFromArgs``,
``_Py_InitializeFromWideArgs``, ``_PyFloat_Repr``, ``_PyFloat_Digits``,
``_PyFloat_DigitsInit``, ``PyFrame_ExtendStack``, ``_PyAIterWrapper_Type``,
``PyNullImporter_Type``, ``PyCmpWrapper_Type``, ``PySortWrapper_Type``,
``PyNoArgsFunction``.
..
.. bpo: 39164
.. date: 2019-12-30-10-43-52
.. nonce: WEV0uu
.. section: C API
Add a private ``_PyErr_GetExcInfo()`` function to retrieve exception
information of the specified Python thread state.

.. date: 2025-02-25-10-25-27
.. gh-issue: 128540
.. nonce: QDz3OL
.. release date: 2025-03-14
.. section: macOS
Ensure web browser is launched by :func:`webbrowser.open` on macOS, even for
``file://`` URLs.
..
.. date: 2025-03-09-19-57-35
.. gh-issue: 131020
.. nonce: _c87wf
.. section: Windows
:source:`pylauncher <PC/launcher2.c>` correctly detects a BOM when searching
for the shebang. Fix by Chris Eibl.
..
.. date: 2025-02-28-23-24-03
.. gh-issue: 130453
.. nonce: EK0Vk_
.. section: Tools/Demos
Make it possible to override default keywords in :program:`pygettext`.
..
.. date: 2025-02-24-21-36-23
.. gh-issue: 85012
.. nonce: 9K1U0E
.. section: Tools/Demos
Correctly reset ``msgctxt`` when compiling messages in :program:`msgfmt`.
..
.. date: 2025-02-22-18-08-35
.. gh-issue: 130453
.. nonce: njRXG8
.. section: Tools/Demos
Extend support for specifying custom keywords in :program:`pygettext`.
..
.. date: 2025-02-16-19-00-00
.. gh-issue: 130195
.. nonce: 19274
.. section: Tools/Demos
Add warning messages when ``pygettext`` unimplemented ``-a/--extract-all``
option is called.
..
.. date: 2025-02-12-23-24-37
.. gh-issue: 130057
.. nonce: TKUKI6
.. section: Tools/Demos
Add support for translator comments in :program:`pygettext.py`.
..
.. date: 2025-02-12-14-58-54
.. gh-issue: 130025
.. nonce: _-mp5K
.. section: Tools/Demos
The iOS testbed now correctly handles symlinks used as Python framework
references.
..
.. date: 2025-02-09-20-29-06
.. gh-issue: 129911
.. nonce: uMFtf1
.. section: Tools/Demos
Fix the keyword entry in the help output of :program:`pygettext`.
..
.. date: 2025-02-26-15-10-16
.. gh-issue: 129200
.. nonce: XH4TeC
.. section: Tests
Multiple iOS testbed runners can now be started at the same time without
introducing an ambiguity over simulator ownership.
..
.. date: 2025-02-20-13-50-07
.. gh-issue: 130292
.. nonce: RvK2Ou
.. section: Tests
The iOS testbed will now run successfully on a machine that has not
previously run Xcode tests (such as CI configurations).
..
.. date: 2025-02-20-13-39-12
.. gh-issue: 130293
.. nonce: 5igSsu
.. section: Tests
The tests of terminal colorization are no longer sensitive to the value of
the ``TERM`` variable in the testing environment.
..
.. date: 2025-02-10-14-34-29
.. gh-issue: 129401
.. nonce: Cq6Ruy
.. section: Tests
Fix a flaky test in ``test_repr_rlock`` that checks the representation of
:class:`multiprocessing.RLock`.
..
.. date: 2025-01-26-20-17-58
.. gh-issue: 126332
.. nonce: c0wUS-
.. section: Tests
Add unit tests for pyrepl.
..
.. date: 2024-11-28-20-29-21
.. gh-issue: 127371
.. nonce: PeEhUd
.. section: Security
Avoid unbounded buffering for
:meth:`!tempfile.SpooledTemporaryFile.writelines`. Previously, disk
spillover was only checked after the lines iterator had been exhausted. This
is now done after each line is written.
..
.. date: 2025-03-14-09-28-13
.. gh-issue: 131204
.. nonce: wogNEX
.. section: Library
Use monospace font from System Font Stack for cross-platform support in
:class:`difflib.HtmlDiff`.
..
.. date: 2025-03-13-19-53-57
.. gh-issue: 131196
.. nonce: 3sBFv2
.. section: Library
Improve performance of :attr:`uuid.UUID.hex` and :meth:`uuid.UUID.__str__
<object.__str__>`.
..
.. date: 2025-03-13-07-06-22
.. gh-issue: 130940
.. nonce: i5cUI5
.. section: Library
The behavior of ``PyConfig.use_system_logger`` was modified to be enabled by
default on iOS. It remains disabled by default on macOS.
..
.. date: 2025-03-11-23-58-45
.. gh-issue: 131123
.. nonce: WB6tPh
.. section: Library
Supported completions for attributes of convenience variables in :mod:`pdb`.
..
.. date: 2025-03-11-20-35-41
.. gh-issue: 93096
.. nonce: Jdt_8a
.. section: Library
Removed undocumented CLI ``python -m difflib``. Use ``python -m doctest
Lib/difflib.py -v`` instead. Patch by Semyon Moroz.
..
.. date: 2025-03-11-08-07-07
.. gh-issue: 93096
.. nonce: DyPXUX
.. section: Library
Removed undocumented ``-t`` and ``-v`` arguments of ``python -m pickle``.
Use ``python -m doctest Lib/pickle.py -v`` instead. Patch by Semyon Moroz.
..
.. date: 2025-03-10-20-23-00
.. gh-issue: 81267
.. nonce: a39381
.. section: Library
Correct :func:`time.sleep` error message when an object that cannot be
interpreted as an integer or float is provided.
..
.. date: 2025-03-10-14-44-04
.. gh-issue: 93096
.. nonce: kmt59U
.. section: Library
Removed undocumented ``-t`` and ``-v`` arguments of ``python -m
pickletools``. Use ``python -m doctest Lib/pickletools.py -v`` instead.
Patch by Semyon Moroz.
..
.. date: 2025-03-10-12-26-56
.. gh-issue: 131045
.. nonce: s1TssJ
.. section: Library
Fix issue with ``__contains__``, values, and pseudo-members for
:class:`enum.Flag`.
..
.. date: 2025-03-07-19-24-27
.. gh-issue: 130959
.. nonce: xO8vVS
.. section: Library
Fix pure-Python implementation of :func:`datetime.time.fromisoformat` to
reject times with spaces in fractional part (for example, ``12:34:56.400
+02:00``), matching the C implementation. Patch by Michał Gorny.
..
.. date: 2025-03-05-20-02-21
.. gh-issue: 130806
.. nonce: o0l2FJ
.. section: Library
Deleting :class:`gzip.GzipFile` before it is closed now emits a
:exc:`ResourceWarning`.
..
.. date: 2025-03-01-02-19-28
.. gh-issue: 130637
.. nonce: swet54w4rs
.. section: Library
Add validation for numeric response data in poplib.POP3.stat() method
..
.. date: 2025-02-28-11-56-19
.. gh-issue: 130665
.. nonce: cfksVk
.. section: Library
Only apply locale to :ref:`calendar CLI <calendar-cli>` when set via
``--locale`` and not via ``LANG`` environment variable.
..
.. date: 2025-02-28-01-10-14
.. gh-issue: 130660
.. nonce: VIThEz
.. section: Library
``sys.ps1`` and ``sys.ps2`` are now restored after :func:`code.interact`
call.
..
.. date: 2025-02-26-21-21-08
.. gh-issue: 130608
.. nonce: f7ix0Y
.. section: Library
Remove *dirs_exist_ok* argument from :meth:`pathlib.Path.copy` and
:meth:`~pathlib.Path.copy_into`. These methods are new in Python 3.14.
..
.. date: 2025-02-25-03-53-00
.. gh-issue: 130461
.. nonce: asr2dg
.. section: Library
Remove ``.. index::`` directives from the :mod:`uuid` module documentation.
These directives previously created entries in the general index for
:func:`~uuid.getnode` as well as the :func:`~uuid.uuid1`,
:func:`~uuid.uuid3`, :func:`~uuid.uuid4`, :func:`~uuid.uuid5`, and
:func:`~uuid.uuid8` constructor functions.
..
.. date: 2025-02-24-14-46-20
.. gh-issue: 130379
.. nonce: lsef7A
.. section: Library
The zipapp module now calculates the list of files to be added to the
archive before creating the archive. This avoids accidentally including the
target when it is being created in the source directory.
..
.. date: 2025-02-24-01-49-11
.. gh-issue: 82987
.. nonce: vHfQlG
.. section: Library
Inline breakpoints like :func:`breakpoint` or :func:`pdb.set_trace` will
always stop the program at calling frame, ignoring the ``skip`` pattern (if
any).
..
.. date: 2025-02-22-19-44-00
.. gh-issue: 125377
.. nonce: LFTK0H
.. section: Library
``<tab>`` at the beginning of the line in :mod:`pdb` multi-line input will
fill in a 4-space indentation now, instead of inserting a ``\t`` character.
..
.. date: 2025-02-21-21-50-21
.. gh-issue: 125413
.. nonce: DEAD0L
.. section: Library
Ensure the path returned from :meth:`pathlib.Path.copy` or
:meth:`~pathlib.Path.move` has fresh :attr:`~pathlib.Path.info`.
..
.. date: 2025-02-21-20-22-45
.. gh-issue: 65697
.. nonce: BLxt6y
.. section: Library
stdlib configparser will now attempt to validate that keys it writes will
not result in file corruption (creating a file unable to be accurately
parsed by a future read() call from the same parser). Attempting a
corrupting write() will raise an InvalidWriteError.
..
.. date: 2025-02-21-20-16-32
.. gh-issue: 125413
.. nonce: YJ7Msf
.. section: Library
Speed up :meth:`Path.copy <pathlib.Path.copy>` by making better use of
:attr:`~pathlib.Path.info` internally.
..
.. date: 2025-02-21-10-32-05
.. gh-issue: 130285
.. nonce: C0fkh7
.. section: Library
Fix corner case for :func:`random.sample` allowing the *counts* parameter to
specify an empty population. So now, ``sample([], 0, counts=[])`` and
``sample('abc', k=0, counts=[0, 0, 0])`` both give the same result as
``sample([], 0)``.
..
.. date: 2025-02-21-09-05-44
.. gh-issue: 124703
.. nonce: AMJD4Y
.. section: Library
Executing ``quit`` command in :mod:`pdb` will raise :exc:`bdb.BdbQuit` when
:mod:`pdb` is started from an interactive console using :func:`breakpoint`
or :func:`pdb.set_trace`.
..
.. date: 2025-02-19-20-29-33
.. gh-issue: 107773
.. nonce: 7y6Ug2
.. section: Library
Make :mod:`datetime` subclass :meth:`~object.__repr__` consistent both
implementations. Patch by Semyon Moroz.
..
.. date: 2025-02-19-19-29-19
.. gh-issue: 130250
.. nonce: T00tql
.. section: Library
Fix regression in ``traceback.print_last()``.
..
.. date: 2025-02-19-08-06-37
.. gh-issue: 123471
.. nonce: br7uyR
.. section: Library
Make concurrent iterations over :class:`itertools.batched` safe under
free-threading.
..
.. date: 2025-02-19-01-29-16
.. gh-issue: 57537
.. nonce: 4tdVuK
.. section: Library
Support breakpoints for :mod:`zipimport` modules on :mod:`pdb`
..
.. date: 2025-02-17-21-16-51
.. gh-issue: 130230
.. nonce: 9ta9P9
.. section: Library
Fix crash in :func:`pow` with only :class:`~decimal.Decimal` third argument.
..
.. date: 2025-02-17-21-01-25
.. gh-issue: 126944
.. nonce: 49YTHZ
.. section: Library
Show explicit errors when required arguments of :mod:`pdb` commands are
missing
..
.. date: 2025-02-17-12-36-39
.. gh-issue: 127750
.. nonce: ZC-hBq
.. section: Library
Improve repr of :class:`functools.singledispatchmethod` methods and
descriptors.
..
.. date: 2025-02-16-18-13-40
.. gh-issue: 128520
.. nonce: iZtOMz
.. section: Library
Apply type conversion consistently in :class:`pathlib.PurePath` and
:class:`~pathlib.Path` methods can accept a path object as an argument, such
as :meth:`~pathlib.PurePath.match` and :meth:`~pathlib.Path.rename`. The
argument is now converted to path object if it lacks a
:meth:`~pathlib.PurePath.with_segments` attribute, and not otherwise.
..
.. date: 2025-02-16-10-12-27
.. gh-issue: 118761
.. nonce: TNw5ZC
.. section: Library
Reverts a change in the previous release attempting to make some stdlib
imports used within the :mod:`subprocess` module lazy as this was causing
errors during ``__del__`` finalizers calling methods such as ``terminate``,
or ``kill``, or ``send_signal``.
..
.. date: 2025-02-16-08-56-48
.. gh-issue: 130164
.. nonce: vvoaU2
.. section: Library
Fixed failure to raise :exc:`TypeError` in :meth:`inspect.Signature.bind`
for positional-only arguments provided by keyword when a variadic keyword
argument (e.g. ``**kwargs``) is present.
..
.. date: 2025-02-15-12-36-49
.. gh-issue: 130151
.. nonce: 3IFumF
.. section: Library
Fix reference leaks in :func:`!_hashlib.hmac_new` and
:func:`!_hashlib.hmac_digest`. Patch by Bénédikt Tran.
..
.. date: 2025-02-15-07-50-37
.. gh-issue: 130145
.. nonce: I0CkV0
.. section: Library
Fix :meth:`!asyncio.AbstractEventloop.run_forever` when another loop is
already running.
..
.. date: 2025-02-15-01-37-47
.. gh-issue: 130139
.. nonce: gntc7B
.. section: Library
Fix bug where :func:`ast.parse` did not error on AST input which is not of
the correct type, when called with optimize=False.
..
.. date: 2025-02-14-23-38-03
.. gh-issue: 127260
.. nonce: dXQ8P0
.. section: Library
Forbid the use of colon (":") as a fractional component separator and other
improvements to the consistency of error raising between the C and Python
implementations of :meth:`datetime.time.fromisoformat` and
:meth:`datetime.datetime.fromisoformat`. Patch by Semyon Moroz.
..
.. date: 2025-02-13-15-10-56
.. gh-issue: 85795
.. nonce: jeXXI9
.. section: Library
Using :func:`super` and ``__class__`` :term:`closure variable` in
user-defined methods of :class:`typing.NamedTuple` subclasses is now
explicitly prohibited at runtime. Contributed by Bartosz Sławecki in
:gh:`130082`.
..
.. date: 2025-02-13-02-03-38
.. gh-issue: 118761
.. nonce: le_qEg
.. section: Library
Improve import time of :mod:`cmd` by lazy importing :mod:`inspect` and
removing :mod:`string`. Patch by Semyon Moroz.
..
.. date: 2025-02-12-12-38-24
.. gh-issue: 129726
.. nonce: jB0sxu
.. section: Library
Fix :class:`gzip.GzipFile` raising an unraisable exception during garbage
collection when referring to a temporary object by breaking the reference
loop with :mod:`weakref`.
..
.. date: 2025-02-11-18-37-26
.. gh-issue: 127750
.. nonce: 41SDhF
.. section: Library
Remove broken :func:`functools.singledispatchmethod` caching introduced in
:gh:`85160`. Achieve the same performance using different optimization.
..
.. date: 2025-02-11-06-42-17
.. gh-issue: 129948
.. nonce: ZcugY9
.. section: Library
Add support for shared :class:`set` to
:class:`multiprocessing.managers.SyncManager` via :meth:`SyncManager.set()
<multiprocessing.managers.SyncManager.set>`.
..
.. date: 2025-02-10-19-16-48
.. gh-issue: 129965
.. nonce: B6wik0
.. section: Library
Update MIME types for ``.avi`` and ``.wav``. Add MIME types for ``.docx``,
``.pptx``, ``.xlsx``, ``.epub``, ``.flac``, ``.m4a``, ``.odg``, ``.odp``,
``.ods``, ``.odt``, ``.oga``, ``.ogg``, ``.ogx`` and ``.weba``. Patch by
Hugo van Kemenade.
..
.. date: 2025-02-10-09-45-49
.. gh-issue: 129889
.. nonce: PBHXU5
.. section: Library
Support context manager protocol by :class:`contextvars.Token`. Patch by
Andrew Svetlov.
..
.. date: 2025-02-08-15-13-43
.. gh-issue: 97850
.. nonce: jQ0CvW
.. section: Library
Update the deprecation warning of ``importlib.abc.Loader.load_module``.
..
.. date: 2025-02-05-15-17-31
.. gh-issue: 129678
.. nonce: GIUrmV
.. section: Library
:class:`configparser.ConfigParser`: do not write an empty unnamed section
..
.. date: 2025-02-02-23-47-35
.. gh-issue: 128641
.. nonce: GFs673
.. section: Library
Restore :meth:`configparser.ConfigParser.read` performance.
..
.. date: 2025-02-02-16-30-27
.. gh-issue: 129569
.. nonce: i0kPOG
.. section: Library
Fix :func:`unicodedata.normalize` to always return a built-in :class:`str`
object when given an input of a :class:`str` subclass, regardless of whether
the string is already normalized.
..
.. date: 2025-01-30-22-49-42
.. gh-issue: 128231
.. nonce: SuEC18
.. section: Library
Execution of multiple statements in the new REPL now stops immediately upon
the first exception encountered. Patch by Bartosz Sławecki.
..
.. date: 2025-01-26-19-35-06
.. gh-issue: 96092
.. nonce: mMg3gL
.. section: Library
Fix bug in :func:`traceback.walk_stack` called with None where it was
skipping more frames than in prior versions. This bug fix also changes
walk_stack to walk the stack in the frame where it was called rather than
where it first gets used.
..
.. date: 2025-01-26-15-35-53
.. gh-issue: 129288
.. nonce: wB3uxU
.. section: Library
Add optional ``l2_cid`` and ``l2_bdaddr_type`` fields to :mod:`socket`
``BTPROTO_L2CAP`` sockaddr tuple.
..
.. date: 2025-01-15-12-04-30
.. gh-issue: 128703
.. nonce: 6WPf38
.. section: Library
Fix :func:`mimetypes.guess_type` to use default mapping for empty
``Content-Type`` in registry.
..
.. date: 2025-01-08-15-14-17
.. gh-issue: 128647
.. nonce: GabglU
.. section: Library
Eagerly write to buffers passed to :class:`gzip.GzipFile`'s
:meth:`~io.BufferedIOBase.readinto` and :meth:`~io.BufferedIOBase.readinto1`
implementations, avoiding unnecessary allocations. Patch by Chris
Markiewicz.
..
.. date: 2024-12-23-17-00-35
.. gh-issue: 128184
.. nonce: cRQvgM
.. section: Library
Improve display of :class:`annotationlib.ForwardRef` object within
:class:`inspect.Signature` representations. This also fixes a
:exc:`NameError` that was raised when using :func:`dataclasses.dataclass` on
classes with unresolvable forward references.
..
.. date: 2024-12-17-18-53-21
.. gh-issue: 128041
.. nonce: W96kAr
.. section: Library
Add :meth:`concurrent.futures.ProcessPoolExecutor.terminate_workers` and
:meth:`concurrent.futures.ProcessPoolExecutor.kill_workers` as ways to
terminate or kill all living worker processes in the given pool.
(Contributed by Charles Machalow in :gh:`130849`.)
..
.. date: 2024-12-05-19-54-16
.. gh-issue: 127647
.. nonce: Xd78Vs
.. section: Library
Add protocols :class:`io.Reader` and :class:`io.Writer` as alternatives to
:class:`typing.IO`, :class:`typing.TextIO`, and :class:`typing.BinaryIO`.
..
.. date: 2024-11-27-23-29-05
.. gh-issue: 109798
.. nonce: OPj1CT
.. section: Library
Added additional information into error messages in :mod:`datetime`, and
made the messages more consistent between the C and Python implementations.
Patch by Semyon Moroz.
..
.. date: 2024-10-20-13-01-05
.. gh-issue: 125746
.. nonce: wDLTay
.. section: Library
Delay deprecated :meth:`!zipimport.zipimporter.load_module` removal time to
3.15. Use :meth:`zipimport.zipimporter.exec_module` instead.
..
.. date: 2024-10-18-10-27-54
.. gh-issue: 74028
.. nonce: 4d4vVD
.. section: Library
Add the optional ``buffersize`` parameter to
:meth:`concurrent.futures.Executor.map` to limit the number of submitted
tasks whose results have not yet been yielded. If the buffer is full,
iteration over the *iterables* pauses until a result is yielded from the
buffer.
..
.. date: 2024-10-05-13-25-07
.. gh-issue: 124927
.. nonce: uzNA32
.. section: Library
Non-printing characters are now properly handled in the new REPL.
..
.. date: 2024-09-16-17-03-52
.. gh-issue: 124096
.. nonce: znin0O
.. section: Library
Turn on virtual terminal mode and enable bracketed paste in REPL on Windows
console. (If the terminal does not support bracketed paste, enabling it does
nothing.)
..
.. date: 2024-06-28-11-27-25
.. gh-issue: 89083
.. nonce: DKL_Sk
.. section: Library
Add :func:`uuid.uuid7` for generating UUIDv7 objects as specified in
:rfc:`9562`. Patch by Bénédikt Tran.
..
.. date: 2024-06-17-17-31-27
.. gh-issue: 89083
.. nonce: nW00Yq
.. section: Library
Add :func:`uuid.uuid6` for generating UUIDv6 objects as specified in
:rfc:`9562`. Patch by Bénédikt Tran.
..
.. date: 2024-04-30-14-03-09
.. gh-issue: 117151
.. nonce: yt2H8c
.. section: Library
Increase ``io.DEFAULT_BUFFER_SIZE`` from 8k to 128k and adjust :func:`open`
on platforms where :meth:`os.fstat` provides a ``st_blksize`` field (such as
Linux) to use ``max(min(blocksize, 8 MiB), io.DEFAULT_BUFFER_SIZE)`` rather
than always using the device block size. This should improve I/O
performance. Patch by Romain Morotti.
..
.. date: 2023-06-08-07-56-05
.. gh-issue: 105499
.. nonce: 7jV6cP
.. section: Library
Make :class:`types.UnionType` an alias for :class:`typing.Union`. Both ``int
| str`` and ``Union[int, str]`` now create instances of the same type. Patch
by Jelle Zijlstra.
..
.. date: 2022-05-28-19-41-02
.. gh-issue: 93096
.. nonce: qjUyRG
.. section: Library
Document the command-line for :mod:`mimetypes`. It now exits with ``1`` on
failure instead of ``0`` and ``2`` on incorrect command-line parameters
instead of ``1``. Also, errors are printed to stderr instead of stdout and
their text is made tighter. Patch by Oleg Iarygin and Hugo van Kemenade.
..
.. date: 2025-02-22-02-24-39
.. gh-issue: 125722
.. nonce: zDIUFV
.. section: Documentation
Require Sphinx 8.2.0 or later to build the Python documentation. Patch by
Adam Turner.
..
.. date: 2025-02-21-08-44-31
.. gh-issue: 129712
.. nonce: 4AcfWQ
.. section: Documentation
The wheel tags supported by each macOS universal SDK option are now
documented.
..
.. date: 2025-02-16-14-57-00
.. gh-issue: 46236
.. nonce: 2HuS4S
.. section: Documentation
C API: Document :c:func:`PyUnicode_RSplit`, :c:func:`PyUnicode_Partition`
and :c:func:`PyUnicode_RPartition`.
..
.. date: 2025-03-12-11-19-46
.. gh-issue: 131141
.. nonce: tQz594
.. section: Core and Builtins
Fix data race in :data:`sys.monitoring` instrumentation while registering
callback.
..
.. date: 2025-03-10-21-46-37
.. gh-issue: 130804
.. nonce: 0PpcTx
.. section: Core and Builtins
Fix support of unicode characters on Windows in the new REPL.
..
.. date: 2025-03-06-22-56-02
.. gh-issue: 130932
.. nonce: QVHaKT
.. section: Core and Builtins
Fix incorrect exception handling in ``_PyModule_IsPossiblyShadowing``
..
.. date: 2025-03-05-21-52-20
.. gh-issue: 122029
.. nonce: d_z93q
.. section: Core and Builtins
:func:`sys.setprofile` and :func:`sys.settrace` will not generate a
``c_call`` event for ``INSTRUMENTED_CALL_FUNCTION_EX`` if the callable is a
method with a C function wrapped, because we do not generate ``c_return``
event in such case.
..
.. date: 2025-03-05-15-19-21
.. gh-issue: 129964
.. nonce: jqu89w
.. section: Core and Builtins
Fix JIT crash on Windows on Arm. Patch by Diego Russo and Brandt Bucher.
..
.. date: 2025-03-04-20-33-28
.. gh-issue: 130851
.. nonce: MT9j7n
.. section: Core and Builtins
Fix a crash in the :term:`free threading` build when constructing a
:class:`code` object with :attr:`~codeobject.co_consts` that contains
instances of types that are not otherwise generated by the bytecode
compiler.
..
.. date: 2025-03-04-15-12-32
.. gh-issue: 128534
.. nonce: 3A0K3D
.. section: Core and Builtins
Ensure that both left and right branches have the same source for ``async
for`` loops. Add these branches to the ``co_branches()`` iterator.
..
.. date: 2025-03-03-20-33-44
.. gh-issue: 130794
.. nonce: LwtGQc
.. section: Core and Builtins
Fix memory leak in the :term:`free threaded <free threading>` build when
resizing a shared list or dictionary from multiple short-lived threads.
..
.. date: 2025-03-03-01-21-04
.. gh-issue: 130415
.. nonce: ibOV6B
.. section: Core and Builtins
Improve JIT understanding of integers in boolean context.
..
.. date: 2025-02-28-16-13-02
.. gh-issue: 130382
.. nonce: 66VTmy
.. section: Core and Builtins
Fix ``PyRefTracer_DESTROY`` not being sent from :file:`Python/ceval.c`
``Py_DECREF()``.
..
.. date: 2025-02-28-13-34-51
.. gh-issue: 130574
.. nonce: ujr3Vx
.. section: Core and Builtins
Renumber :opcode:`RESUME` from 149 to 128.
..
.. date: 2025-02-27-18-48-42
.. gh-issue: 124878
.. nonce: DS0MIL
.. section: Core and Builtins
Fix race conditions during runtime finalization that could lead to accessing
freed memory.
..
.. date: 2025-02-27-17-05-05
.. gh-issue: 130415
.. nonce: iijvfW
.. section: Core and Builtins
Improve the experimental JIT's ability to narrow boolean values based on the
results of truthiness tests.
..
.. date: 2025-02-27-15-07-06
.. gh-issue: 130618
.. nonce: JTcsRB
.. section: Core and Builtins
Fix a bug that was causing ``UnicodeDecodeError`` or ``SystemError`` to be
raised when using f-strings with ``lambda`` expressions with non-ASCII
characters. Patch by Pablo Galindo
..
.. date: 2025-02-27-10-47-09
.. gh-issue: 123044
.. nonce: 8182Un
.. section: Core and Builtins
Make sure that the location of branch targets in ``match`` cases is in the
body, not the pattern.
..
.. date: 2025-02-26-10-32-48
.. gh-issue: 128534
.. nonce: JEiQex
.. section: Core and Builtins
Add branch monitoring (``BRANCH_LEFT`` and ``BRANCH_RIGHT`` events) for
``async for`` loops.
..
.. date: 2025-02-24-14-25-36
.. gh-issue: 130163
.. nonce: rGpc9v
.. section: Core and Builtins
Fix possible crashes related to concurrent change and use of the :mod:`sys`
module attributes.
..
.. date: 2025-02-23-20-48-31
.. gh-issue: 122029
.. nonce: iW8GvA
.. section: Core and Builtins
``INSTRUMENTED_CALL_KW`` will expand the method before monitoring to reflect
the actual behavior more accurately.
..
.. date: 2025-02-22-22-49-00
.. gh-issue: 130415
.. nonce: WyxBYS
.. section: Core and Builtins
Improve JIT's ability to optimize strings in boolean contexts.
..
.. date: 2025-02-21-11-12-41
.. gh-issue: 130396
.. nonce: SIenSP
.. section: Core and Builtins
Use actual stack limits (from  :manpage:`pthread_getattr_np(3)`) for linux,
and other systems with ``_GNU_SOURCE`` defined, when determining limits for
C stack protection.
..
.. date: 2025-02-17-18-59-33
.. gh-issue: 128396
.. nonce: iVtoYY
.. section: Core and Builtins
Fix a crash that occurs when calling :func:`locals` inside an inline
comprehension that uses the same local variable as the outer frame scope
where the variable is a free or cell var.
..
.. date: 2025-02-17-15-32-26
.. gh-issue: 129107
.. nonce: fPPBLw
.. section: Core and Builtins
Fix two more :class:`bytearray` functions for :term:`free threading`.
..
.. date: 2025-02-17-12-48-00
.. gh-issue: 127705
.. nonce: Qad2hx
.. section: Core and Builtins
Use tagged references (``_PyStackRef``) for the default build as well as for
the free-threading build. This has a small negative performance impact
short-term but will enable larger speedups in the future and significantly
reduce maintenance costs by allowing a single implementation of tagged
references in the future.
..
.. date: 2025-02-14-00-32-52
.. gh-issue: 130094
.. nonce: m3EF9E
.. section: Core and Builtins
Fix two race conditions involving concurrent imports that could lead to
spurious failures with :exc:`ModuleNotFoundError`.
..
.. date: 2025-02-13-20-42-53
.. gh-issue: 129107
.. nonce: _olg-L
.. section: Core and Builtins
Make :class:`bytearray` iterator safe under :term:`free threading`.
..
.. date: 2025-02-13-12-31-53
.. gh-issue: 115802
.. nonce: 0kN4xM
.. section: Core and Builtins
Use the more efficient "medium" code model for JIT-compiled code on
supported platforms.
..
.. date: 2025-02-13-02-39-42
.. gh-issue: 107956
.. nonce: dLguDW
.. section: Core and Builtins
A ``build-details.json`` file is now install in the platform-independent
standard library directory (:pep:`739` implementation).
..
.. date: 2025-02-13-00-28-43
.. gh-issue: 116042
.. nonce: 861juq
.. section: Core and Builtins
Fix location for SyntaxErrors of invalid escapes in the tokenizer. Patch by
Pablo Galindo
..
.. date: 2025-02-12-12-44-36
.. gh-issue: 91079
.. nonce: 8Nq08d
.. section: Core and Builtins
Change C stack overflow protection to consider the amount of stack consumed,
rather than a counter. This allows deeper recursion in many cases, but
remains safe.
..
.. date: 2025-02-11-22-20-21
.. gh-issue: 129715
.. nonce: mopO8n
.. section: Core and Builtins
Improve the experimental JIT's handling of returns to unknown callers.
..
.. date: 2025-02-11-20-38-37
.. gh-issue: 129983
.. nonce: _1Fujo
.. section: Library
Fix data race in compile_template in :file:`sre.c`.
..
.. date: 2025-02-10-20-01-56
.. gh-issue: 129967
.. nonce: J60tEl
.. section: Core and Builtins
Fix a race condition in the :term:`free threading` build when ``repr(set)``
is called concurrently with ``set.clear()``.
..
.. date: 2025-02-10-11-30-13
.. gh-issue: 129953
.. nonce: wipsl_
.. section: Core and Builtins
The internal (evaluation) stack is now spilled to memory whenever execution
escapes from the interpreter or JIT compiled code. This should have no
observable effect in either Python or builtin extensions, but will allow
various important optimizations in the future.
..
.. date: 2025-02-09-11-30-38
.. gh-issue: 129515
.. nonce: 3L3vmo
.. section: Core and Builtins
Clarify syntax error messages for conditional expressions when a statement
is specified before an :keyword:`if` or after an :keyword:`else` keyword.
..
.. date: 2025-02-08-09-55-33
.. gh-issue: 129349
.. nonce: PkcG-l
.. section: Core and Builtins
:meth:`bytes.fromhex` and :meth:`bytearray.fromhex` now accepts ASCII
:class:`bytes` and :term:`bytes-like objects <bytes-like object>`.
..
.. date: 2025-01-25-20-07-03
.. gh-issue: 129149
.. nonce: njeFJi
.. section: Core and Builtins
Add fast path for medium-size integers in :c:func:`PyLong_FromSsize_t`.
Patch by Chris Eibl.
..
.. date: 2025-01-20-23-34-14
.. gh-issue: 129107
.. nonce: T5gBva
.. section: Core and Builtins
Make the :type:`bytearray` safe under :term:`free threading`.
..
.. date: 2025-01-18-10-50-04
.. gh-issue: 128974
.. nonce: KltI-A
.. section: Core and Builtins
Fix a crash in :meth:`UnicodeError.__str__ <object.__str__>` when custom
attributes implement :meth:`~object.__str__` with side-effects. Patch by
Bénédikt Tran.
..
.. date: 2024-12-15-16-56-26
.. gh-issue: 126085
.. nonce: BvyEXk
.. section: Core and Builtins
:class:`typing.TypeAliasType` now supports star unpacking.
..
.. date: 2024-10-29-23-30-35
.. gh-issue: 125331
.. nonce: quKQ7V
.. section: Core and Builtins
``from __future__ import barry_as_FLUFL`` now works in more contexts,
including when it is used in files, with the ``-c`` flag, and in the REPL
when there are multiple statements on the same line. Previously, it worked
only on subsequent lines in the REPL, and when the appropriate flags were
passed directly to :func:`compile`. Patch by Pablo Galindo.
..
.. date: 2024-10-19-20-22-19
.. gh-issue: 121464
.. nonce: IHwfpK
.. section: Core and Builtins
Make concurrent iterations over the same :func:`enumerate` iterator safe
under free-threading. See `Strategy for Iterators in Free Threading
<https://github.com/python/cpython/issues/124397>`_.
..
.. date: 2024-10-11-10-41-05
.. gh-issue: 87790
.. nonce: mlfEGl
.. section: Core and Builtins
Support underscore and comma as thousands separators in the fractional part
for floating-point presentation types of the new-style string formatting
(with :func:`format` or :ref:`f-strings`).  Patch by Sergey B Kirpichev.
..
.. date: 2024-09-25-13-45-01
.. gh-issue: 124445
.. nonce: zfsD7q
.. section: Core and Builtins
Fix specialization of generic aliases that are generic over a
:class:`typing.ParamSpec` and have been specialized with a nested type
variable.
..
.. date: 2024-06-24-20-08-55
.. gh-issue: 120608
.. nonce: d75n8U
.. section: Core and Builtins
Adapt :func:`reversed` for use in the free-threading build. The
:func:`reversed` is still not thread-safe in the sense that concurrent
iterations may see the same object, but they will not corrupt the
interpreter state.
..
.. date: 2022-12-21-14-28-01
.. gh-issue: 100388
.. nonce: vne8ky
.. section: Library
Fix the ``platform._sys_version()`` method when ``__DATE__`` is undefined at
buildtime by changing default buildtime datetime string to the UNIX epoch.
..
.. bpo: 44369
.. date: 2021-06-09-23-04-58
.. nonce: R7QkFv
.. section: Core and Builtins
Improve syntax errors for incorrectly closed strings. Patch by Pablo Galindo
..
.. date: 2025-03-12-08-29-23
.. gh-issue: 111178
.. nonce: Jny_YJ
.. section: C API
Fix :c:type:`PyCMethod` API: replace ``size_t nargs`` with ``Py_ssize_t
nargs`` in :c:type:`PyCMethod`. Patch by Victor Stinner.
..
.. date: 2025-03-07-14-49-06
.. gh-issue: 130947
.. nonce: _Pw0IX
.. section: C API
Add again :c:func:`PySequence_Fast` to the limited C API. Patch by Victor
Stinner.
..
.. date: 2025-02-19-14-41-26
.. gh-issue: 128863
.. nonce: TELwyV
.. section: C API
The following private functions are deprecated and planned for removal in
Python 3.18:
* :c:func:`!_PyUnicodeWriter_Init`:
replace ``_PyUnicodeWriter_Init(&writer)`` with
:c:func:`writer = PyUnicodeWriter_Create(0) <PyUnicodeWriter_Create>`.
* :c:func:`!_PyUnicodeWriter_Finish`:
replace ``_PyUnicodeWriter_Finish(&writer)`` with
:c:func:`PyUnicodeWriter_Finish(writer) <PyUnicodeWriter_Finish>`.
* :c:func:`!_PyUnicodeWriter_Dealloc`:
replace ``_PyUnicodeWriter_Dealloc(&writer)`` with
:c:func:`PyUnicodeWriter_Discard(writer) <PyUnicodeWriter_Discard>`.
* :c:func:`!_PyUnicodeWriter_WriteChar`:
replace ``_PyUnicodeWriter_WriteChar(&writer, ch)`` with
:c:func:`PyUnicodeWriter_WriteChar(writer, ch) <PyUnicodeWriter_WriteChar>`.
* :c:func:`!_PyUnicodeWriter_WriteStr`:
replace ``_PyUnicodeWriter_WriteStr(&writer, str)`` with
:c:func:`PyUnicodeWriter_WriteStr(writer, str) <PyUnicodeWriter_WriteStr>`.
* :c:func:`!_PyUnicodeWriter_WriteSubstring`:
replace ``_PyUnicodeWriter_WriteSubstring(&writer, str, start, end)`` with
:c:func:`PyUnicodeWriter_WriteSubstring(writer, str, start, end) <PyUnicodeWriter_WriteSubstring>`.
* :c:func:`!_PyUnicodeWriter_WriteASCIIString`:
replace ``_PyUnicodeWriter_WriteASCIIString(&writer, str)`` with
:c:func:`PyUnicodeWriter_WriteUTF8(writer, str) <PyUnicodeWriter_WriteUTF8>`.
* :c:func:`!_PyUnicodeWriter_WriteLatin1String`:
replace ``_PyUnicodeWriter_WriteLatin1String(&writer, str)`` with
:c:func:`PyUnicodeWriter_WriteUTF8(writer, str) <PyUnicodeWriter_WriteUTF8>`.
* :c:func:`!_PyUnicodeWriter_Prepare`: (no replacement).
* :c:func:`!_PyUnicodeWriter_PrepareKind`: (no replacement).
The `pythoncapi-compat project
<https://github.com/python/pythoncapi-compat/>`__ can be used to get these
new public functions on Python 3.13 and older.
Patch by Victor Stinner.
..
.. date: 2025-02-13-00-57-05
.. gh-issue: 45325
.. nonce: Cwif9z
.. section: C API
Add a new ``p`` format parameter to :c:func:`Py_BuildValue` that allows to
take a C integer and produce a Python :class:`bool` object. Patch by Pablo
Galindo.
..
.. date: 2025-03-10-10-52-25
.. gh-issue: 131035
.. nonce: KF1w4j
.. section: Build
Use ``-flto=thin`` for faster build times using clang-cl on Windows. Patch
by Chris Eibl.
..
.. date: 2025-03-01-18-27-42
.. gh-issue: 130740
.. nonce: nDFSHR
.. section: Build
Ensure that ``Python.h`` is included before ``stdbool.h`` unless
``pyconfig.h`` is included before or in some platform-specific contexts.
..
.. date: 2025-02-13-19-21-41
.. gh-issue: 130090
.. nonce: 3ngJaV
.. section: Build
Building with ``PlatformToolset=ClangCL`` on Windows now supports PGO
(profile guided optimization). Patch by Chris Eibl with invaluable support
from Steve Dover.
..
.. date: 2025-02-11-08-06-44
.. gh-issue: 129819
.. nonce: 7rn4dY
.. section: Build
Allow building the JIT with the tailcall interpreter.
..
.. date: 2025-02-11-07-55-28
.. gh-issue: 129989
.. nonce: kaSKlD
.. section: Build
Fix a bug where the tailcall interpreter was enabled when
``--without-tail-call-interp`` was provided to the configure script.
..
.. date: 2025-02-07-21-20-21
.. gh-issue: 129838
.. nonce: fkuiEc
.. section: Build
Don't redefine ``_Py_NO_SANITIZE_UNDEFINED`` when compiling with a recent
GCC version and undefined sanitizer enabled.
..
.. date: 2023-04-02-14-20-29
.. gh-issue: 82909
.. nonce: LGcZJy
.. section: Build
``#pragma``-based linking with ``python3*.lib`` can now be switched off with
:c:expr:`Py_NO_LINK_LIB`. Patch by Jean-Christophe Fillion-Robin.

.. bpo: 33803
.. date: 2018-06-07-20-18-38
.. nonce: n-Nq6_
.. release date: 2018-06-12
.. section: Core and Builtins
Fix a crash in hamt.c caused by enabling GC tracking for an object that
hadn't all of its fields set to NULL.
..
.. bpo: 33706
.. date: 2018-05-31-14-50-04
.. nonce: ztlH04
.. section: Core and Builtins
Fix a crash in Python initialization when parsing the command line options.
Thanks Christoph Gohlke for the bug report and the fix!
..
.. bpo: 30654
.. date: 2018-05-28-12-28-53
.. nonce: 9fDJye
.. section: Core and Builtins
Fixed reset of the SIGINT handler to SIG_DFL on interpreter shutdown even
when there was a custom handler set previously. Patch by Philipp Kerling.
..
.. bpo: 31849
.. date: 2018-05-14-11-00-00
.. nonce: EmHaH4
.. section: Core and Builtins
Fix signed/unsigned comparison warning in pyhash.c.
..
.. bpo: 30167
.. date: 2018-06-10-19-29-17
.. nonce: G5EgC5
.. section: Library
Prevent site.main() exception if PYTHONSTARTUP is set. Patch by Steve Weber.
..
.. bpo: 33812
.. date: 2018-06-10-13-26-02
.. nonce: frGAOr
.. section: Library
Datetime instance d with non-None tzinfo, but with d.tzinfo.utcoffset(d)
returning None is now treated as naive by the astimezone() method.
..
.. bpo: 30805
.. date: 2018-06-08-17-34-16
.. nonce: 3qCWa0
.. section: Library
Avoid race condition with debug logging
..
.. bpo: 33694
.. date: 2018-06-07-23-51-00
.. nonce: F1zIR1
.. section: Library
asyncio: Fix a race condition causing data loss on
pause_reading()/resume_reading() when using the ProactorEventLoop.
..
.. bpo: 32493
.. date: 2018-06-07-18-55-35
.. nonce: 1Bte62
.. section: Library
Correct test for ``uuid_enc_be`` availability in ``configure.ac``. Patch by
Michael Felt.
..
.. bpo: 33792
.. date: 2018-06-07-12-38-12
.. nonce: 3aKG7u
.. section: Library
Add asyncio.WindowsSelectorEventLoopPolicy and
asyncio.WindowsProactorEventLoopPolicy.
..
.. bpo: 33778
.. date: 2018-06-05-20-22-30
.. nonce: _tSAS6
.. section: Library
Update ``unicodedata``'s database to Unicode version 11.0.0.
..
.. bpo: 33770
.. date: 2018-06-05-11-29-26
.. nonce: oBhxxw
.. section: Library
improve base64 exception message for encoded inputs of invalid length
..
.. bpo: 33769
.. date: 2018-06-04-13-46-39
.. nonce: D_pxYz
.. section: Library
asyncio/start_tls: Fix error message; cancel callbacks in case of an
unhandled error; mark SSLTransport as closed if it is aborted.
..
.. bpo: 33767
.. date: 2018-06-03-22-41-59
.. nonce: 2e82g3
.. section: Library
The concatenation (``+``) and repetition (``*``) sequence operations now
raise :exc:`TypeError` instead of :exc:`SystemError` when performed on
:class:`mmap.mmap` objects.  Patch by Zackery Spytz.
..
.. bpo: 33734
.. date: 2018-06-01-10-55-48
.. nonce: x1W9x0
.. section: Library
asyncio/ssl: Fix AttributeError, increase default handshake timeout
..
.. bpo: 11874
.. date: 2018-05-23-00-26-27
.. nonce: glK5iP
.. section: Library
Use a better regex when breaking usage into wrappable parts. Avoids bogus
assertion errors from custom metavar strings.
..
.. bpo: 33582
.. date: 2018-05-19-15-58-14
.. nonce: qBZPmF
.. section: Library
Emit a deprecation warning for inspect.formatargspec
..
.. bpo: 33409
.. date: 2018-06-08-23-46-01
.. nonce: r4z9MM
.. section: Documentation
Clarified the relationship between :pep:`538`'s PYTHONCOERCECLOCALE and PEP
540's PYTHONUTF8 mode.
..
.. bpo: 33736
.. date: 2018-06-01-12-27-40
.. nonce: JVegIu
.. section: Documentation
Improve the documentation of :func:`asyncio.open_connection`,
:func:`asyncio.start_server` and their UNIX socket counterparts.
..
.. bpo: 31432
.. date: 2017-09-13-07-14-59
.. nonce: yAY4Z3
.. section: Documentation
Clarify meaning of CERT_NONE, CERT_OPTIONAL, and CERT_REQUIRED flags for
ssl.SSLContext.verify_mode.
..
.. bpo: 5755
.. date: 2018-06-04-21-34-34
.. nonce: 65GmCj
.. section: Build
Move ``-Wstrict-prototypes`` option to ``CFLAGS_NODIST`` from ``OPT``. This
option emitted annoying warnings when building extension modules written in
C++.
..
.. bpo: 33720
.. date: 2018-06-04-09-20-53
.. nonce: VKDXHK
.. section: Windows
Reduces maximum marshal recursion depth on release builds.
..
.. bpo: 33656
.. date: 2018-06-10-17-59-36
.. nonce: 60ZqJS
.. section: IDLE
On Windows, add API call saying that tk scales for DPI. On Windows 8.1+ or
10, with DPI compatibility properties of the Python binary unchanged, and a
monitor resolution greater than 96 DPI, this should make text and lines
sharper.  It should otherwise have no effect.
..
.. bpo: 33768
.. date: 2018-06-04-19-23-11
.. nonce: I_2qpV
.. section: IDLE
Clicking on a context line moves that line to the top of the editor window.
..
.. bpo: 33763
.. date: 2018-06-03-20-12-57
.. nonce: URiFlE
.. section: IDLE
IDLE: Use read-only text widget for code context instead of label widget.
..
.. bpo: 33664
.. date: 2018-06-03-09-13-28
.. nonce: PZzQyL
.. section: IDLE
Scroll IDLE editor text by lines. Previously, the mouse wheel and scrollbar
slider moved text by a fixed number of pixels, resulting in partial lines at
the top of the editor box.  The change also applies to the shell and grep
output windows, but not to read-only text views.
..
.. bpo: 33679
.. date: 2018-05-29-07-14-37
.. nonce: MgX_Ui
.. section: IDLE
Enable theme-specific color configuration for Code Context. Use the
Highlights tab to see the setting for built-in themes or add settings to
custom themes.
..
.. bpo: 33642
.. date: 2018-05-24-20-42-44
.. nonce: J0VQbS
.. section: IDLE
Display up to maxlines non-blank lines for Code Context. If there is no
current context, show a single blank line.

.. bpo: 28147
.. date: 9795
.. nonce: CnK_xf
.. release date: 2016-12-16
.. section: Core and Builtins
Fix a memory leak in split-table dictionaries: setattr() must not convert
combined table into split table. Patch written by INADA Naoki.
..
.. bpo: 28990
.. date: 9794
.. nonce: m8xRMJ
.. section: Core and Builtins
Fix asyncio SSL hanging if connection is closed before handshake is
completed. (Patch by HoHo-Ho)
..
.. bpo: 28770
.. date: 9793
.. nonce: N9GQsz
.. section: Tools/Demos
Fix python-gdb.py for fastcalls.
..
.. bpo: 28896
.. date: 9792
.. nonce: ymAbmH
.. section: Windows
Deprecate WindowsRegistryFinder.
..
.. bpo: 28898
.. date: 9791
.. nonce: YGUd_i
.. section: Build
Prevent gdb build errors due to HAVE_LONG_LONG redefinition.

.. bpo: 33001
.. date: 2018-03-05-10-09-51
.. nonce: elj4Aa
.. release date: 2018-03-13
.. section: Security
Minimal fix to prevent buffer overrun in os.symlink on Windows
..
.. bpo: 32981
.. date: 2018-03-02-10-24-52
.. nonce: O_qDyj
.. section: Security
Regexes in difflib and poplib were vulnerable to catastrophic backtracking.
These regexes formed potential DOS vectors (REDOS). They have been
refactored. This resolves :cve:`2018-1060` and :cve:`2018-1061`. Patch by Jamie
Davis.
..
.. bpo: 33026
.. date: 2018-03-08-09-48-38
.. nonce: QZA3Ba
.. section: Core and Builtins
Fixed jumping out of "with" block by setting f_lineno.
..
.. bpo: 17288
.. date: 2018-02-27-13-36-21
.. nonce: Gdj24S
.. section: Core and Builtins
Prevent jumps from 'return' and 'exception' trace events.
..
.. bpo: 32889
.. date: 2018-02-20-21-53-48
.. nonce: J6eWy5
.. section: Core and Builtins
Update Valgrind suppression list to account for the rename of
``Py_ADDRESS_IN_RANG`` to ``address_in_range``.
..
.. bpo: 32650
.. date: 2018-01-28-23-01-39
.. nonce: Bbi7ek
.. section: Core and Builtins
Pdb and other debuggers dependent on bdb.py will correctly step over (next
command) native coroutines. Patch by Pablo Galindo.
..
.. bpo: 32685
.. date: 2018-01-28-12-25-06
.. nonce: nGctze
.. section: Core and Builtins
Improve suggestion when the Python 2 form of print statement is either
present on the same line as the header of a compound statement or else
terminated by a semi-colon instead of a newline. Patch by Nitish Chandra.
..
.. bpo: 32583
.. date: 2018-01-26-21-20-21
.. nonce: Fh3fau
.. section: Core and Builtins
Fix possible crashing in builtin Unicode decoders caused by write
out-of-bound errors when using customized decode error handlers.
..
.. bpo: 26163
.. date: 2018-01-14-20-32-47
.. nonce: xv9Iuv
.. section: Core and Builtins
Improved frozenset() hash to create more distinct hash values when faced
with datasets containing many similar values.
..
.. bpo: 27169
.. date: 2017-12-15-11-50-06
.. nonce: VO84fQ
.. section: Core and Builtins
The ``__debug__`` constant is now optimized out at compile time. This fixes
also bpo-22091.
..
.. bpo: 32329
.. date: 2017-12-15-00-55-35
.. nonce: XL1O99
.. section: Core and Builtins
``sys.flags.hash_randomization`` is now properly set to 0 when hash
randomization is turned off by ``PYTHONHASHSEED=0``.
..
.. bpo: 30416
.. date: 2017-12-14-11-48-19
.. nonce: hlHo_9
.. section: Core and Builtins
The optimizer is now protected from spending much time doing complex
calculations and consuming much memory for creating large constants in
constant folding.
..
.. bpo: 18533
.. date: 2017-12-13-16-46-23
.. nonce: Dlk8d7
.. section: Core and Builtins
``repr()`` on a dict containing its own ``values()`` or ``items()`` no
longer raises ``RecursionError``; OrderedDict similarly.  Instead, use
``...``, as for other recursive structures.  Patch by Ben North.
..
.. bpo: 32028
.. date: 2017-12-03-22-29-13
.. nonce: KC2w4Q
.. section: Core and Builtins
Leading whitespace is now correctly ignored when generating suggestions for
converting Py2 print statements to Py3 builtin print function calls. Patch
by Sanyam Khurana.
..
.. bpo: 32137
.. date: 2017-11-26-14-36-30
.. nonce: Stj5nL
.. section: Core and Builtins
The repr of deeply nested dict now raises a RecursionError instead of
crashing due to a stack overflow.
..
.. bpo: 33064
.. date: 2018-03-12-19-58-25
.. nonce: LO2KIY
.. section: Library
lib2to3 now properly supports trailing commas after ``*args`` and
``**kwargs`` in function signatures.
..
.. bpo: 31804
.. date: 2018-03-11-19-03-52
.. nonce: i8KUMp
.. section: Library
Avoid failing in multiprocessing.Process if the standard streams are closed
or None at exit.
..
.. bpo: 33037
.. date: 2018-03-09-23-07-07
.. nonce: nAJ3at
.. section: Library
Skip sending/receiving data after SSL transport closing.
..
.. bpo: 30353
.. date: 2018-03-08-09-54-01
.. nonce: XdE5aM
.. section: Library
Fix ctypes pass-by-value for structs on 64-bit Cygwin/MinGW.
..
.. bpo: 33009
.. date: 2018-03-06-11-54-59
.. nonce: -Ekysb
.. section: Library
Fix inspect.signature() for single-parameter partialmethods.
..
.. bpo: 32969
.. date: 2018-03-06-00-19-41
.. nonce: rGTKa0
.. section: Library
Expose several missing constants in zlib and fix corresponding
documentation.
..
.. bpo: 32713
.. date: 2018-02-26-13-16-36
.. nonce: 55yegW
.. section: Library
Fixed tarfile.itn handling of out-of-bounds float values. Patch by Joffrey
Fuhrer.
..
.. bpo: 30622
.. date: 2018-02-24-21-40-42
.. nonce: dQjxSe
.. section: Library
The ssl module now detects missing NPN support in LibreSSL.
..
.. bpo: 32922
.. date: 2018-02-23-19-12-04
.. nonce: u-xe0B
.. section: Library
dbm.open() now encodes filename with the filesystem encoding rather than
default encoding.
..
.. bpo: 32859
.. date: 2018-02-19-17-46-31
.. nonce: kAT-Xp
.. section: Library
In ``os.dup2``, don't check every call whether the ``dup3`` syscall exists
or not.
..
.. bpo: 21060
.. date: 2018-02-17-19-20-19
.. nonce: S1Z-x6
.. section: Library
Rewrite confusing message from setup.py upload from "No dist file created in
earlier command" to the more helpful "Must create and upload files in one
command".
..
.. bpo: 32857
.. date: 2018-02-16-14-37-14
.. nonce: -XljAx
.. section: Library
In :mod:`tkinter`, ``after_cancel(None)`` now raises a :exc:`ValueError`
instead of canceling the first scheduled function.  Patch by Cheryl Sabella.
..
.. bpo: 32852
.. date: 2018-02-15-12-04-29
.. nonce: HDqIxM
.. section: Library
Make sure sys.argv remains as a list when running trace.
..
.. bpo: 32841
.. date: 2018-02-14-00-21-24
.. nonce: bvHDOc
.. section: Library
Fixed ``asyncio.Condition`` issue which silently ignored cancellation after
notifying and cancelling a conditional lock. Patch by Bar Harel.
..
.. bpo: 31787
.. date: 2018-02-09-21-41-56
.. nonce: owSZ2t
.. section: Library
Fixed refleaks of ``__init__()`` methods in various modules. (Contributed by
Oren Milman)
..
.. bpo: 30157
.. date: 2018-02-09-14-44-43
.. nonce: lEiiAK
.. section: Library
Fixed guessing quote and delimiter in csv.Sniffer.sniff() when only the last
field is quoted.  Patch by Jake Davis.
..
.. bpo: 32394
.. date: 2018-02-08-08-18-26
.. nonce: 6E_7X7
.. section: Library
socket: Remove TCP_FASTOPEN, TCP_KEEPCNT flags on older version Windows
during run-time.
..
.. bpo: 32777
.. date: 2018-02-05-21-28-28
.. nonce: C-wIXF
.. section: Library
Fix a rare but potential pre-exec child process deadlock in subprocess on
POSIX systems when marking file descriptors inheritable on exec in the child
process.  This bug appears to have been introduced in 3.4.
..
.. bpo: 32647
.. date: 2018-02-05-13-31-42
.. nonce: ktmfR_
.. section: Library
The ctypes module used to depend on indirect linking for dlopen. The shared
extension is now explicitly linked against libdl on platforms with dl.
..
.. bpo: 32734
.. date: 2018-02-01-01-34-47
.. nonce: gCV9AD
.. section: Library
Fixed ``asyncio.Lock()`` safety issue which allowed acquiring and locking
the same lock multiple times, without it being free. Patch by Bar Harel.
..
.. bpo: 32727
.. date: 2018-01-30-17-46-18
.. nonce: aHVsRC
.. section: Library
Do not include name field in SMTP envelope from address. Patch by Stéphane
Wirtel
..
.. bpo: 27931
.. date: 2018-01-25-21-04-11
.. nonce: e4r52t
.. section: Library
Fix email address header parsing error when the username is an empty quoted
string. Patch by Xiang Zhang.
..
.. bpo: 32304
.. date: 2018-01-21-16-33-53
.. nonce: TItrNv
.. section: Library
distutils' upload command no longer corrupts tar files ending with a CR
byte, and no longer tries to convert CR to CRLF in any of the upload text
fields.
..
.. bpo: 32502
.. date: 2018-01-20-17-15-34
.. nonce: OXJfn7
.. section: Library
uuid.uuid1 no longer raises an exception if a 64-bit hardware address is
encountered.
..
.. bpo: 31848
.. date: 2018-01-18-23-34-17
.. nonce: M2cldy
.. section: Library
Fix the error handling in Aifc_read.initfp() when the SSND chunk is not
found. Patch by Zackery Spytz.
..
.. bpo: 32555
.. date: 2018-01-15-17-52-47
.. nonce: CMq2zF
.. section: Library
On FreeBSD and Solaris, os.strerror() now always decode the byte string from
the current locale encoding, rather than using ASCII/surrogateescape in some
cases.
..
.. bpo: 32521
.. date: 2018-01-15-12-53-13
.. nonce: IxX4Ba
.. section: Library
The nis module is now compatible with new libnsl and headers location.
..
.. bpo: 32473
.. date: 2018-01-10-20-37-59
.. nonce: mP_yJG
.. section: Library
Improve ABCMeta._dump_registry() output readability
..
.. bpo: 32521
.. date: 2018-01-08-18-02-33
.. nonce: Kh-KoN
.. section: Library
glibc has removed Sun RPC. Use replacement libtirpc headers and library in
nis module.
..
.. bpo: 32228
.. date: 2017-12-22-16-47-41
.. nonce: waPx3q
.. section: Library
Ensure that ``truncate()`` preserves the file position (as reported by
``tell()``) after writes longer than the buffer size.
..
.. bpo: 26133
.. date: 2017-12-21-11-08-42
.. nonce: mt81QV
.. section: Library
Don't unsubscribe signals in asyncio UNIX event loop on interpreter
shutdown.
..
.. bpo: 32185
.. date: 2017-12-20-09-25-10
.. nonce: IL0cMt
.. section: Library
The SSL module no longer sends IP addresses in SNI TLS extension on
platforms with OpenSSL 1.0.2+ or inet_pton.
..
.. bpo: 32323
.. date: 2017-12-14-10-10-10
.. nonce: ideco
.. section: Library
:func:`urllib.parse.urlsplit` does not convert zone-id (scope) to lower
case for scoped IPv6 addresses in hostnames now.
..
.. bpo: 32302
.. date: 2017-12-13-22-38-08
.. nonce: othtTr
.. section: Library
Fix bdist_wininst of distutils for CRT v142: it binary compatible with CRT
v140.
..
.. bpo: 32255
.. date: 2017-12-12-07-29-06
.. nonce: 2bfNmM
.. section: Library
A single empty field is now always quoted when written into a CSV file. This
allows to distinguish an empty row from a row consisting of a single empty
field. Patch by Licht Takeuchi.
..
.. bpo: 32277
.. date: 2017-12-11-09-53-14
.. nonce: jkKiVC
.. section: Library
Raise ``NotImplementedError`` instead of ``SystemError`` on platforms where
``chmod(..., follow_symlinks=False)`` is not supported.  Patch by Anthony
Sottile.
..
.. bpo: 32199
.. date: 2017-12-04-12-23-26
.. nonce: nGof4v
.. section: Library
The getnode() ip getter now uses 'ip link' instead of 'ip link list'.
..
.. bpo: 27456
.. date: 2017-11-02-11-57-41
.. nonce: snzyTC
.. section: Library
Ensure TCP_NODELAY is set on Linux. Tests by Victor Stinner.
..
.. bpo: 31900
.. date: 2017-10-30-15-55-32
.. nonce: -S9xc4
.. section: Library
The :func:`locale.localeconv` function now sets temporarily the ``LC_CTYPE``
locale to the ``LC_NUMERIC`` locale to decode ``decimal_point`` and
``thousands_sep`` byte strings if they are non-ASCII or longer than 1 byte,
and the ``LC_NUMERIC`` locale is different than the ``LC_CTYPE`` locale.
This temporary change affects other threads.
Same change for the :meth:`str.format` method when formatting a number
(:class:`int`, :class:`float`, :class:`float` and subclasses) with the ``n``
type (ex: ``'{:n}'.format(1234)``).
..
.. bpo: 31802
.. date: 2017-10-17-14-52-14
.. nonce: sYj2Zv
.. section: Library
Importing native path module (``posixpath``, ``ntpath``) now works even if
the ``os`` module still is not imported.
..
.. bpo: 17232
.. date: 2018-02-23-12-48-03
.. nonce: tmuTKL
.. section: Documentation
Clarify docs for -O and -OO.  Patch by Terry Reedy.
..
.. bpo: 32800
.. date: 2018-02-10-15-16-04
.. nonce: FyrqCk
.. section: Documentation
Update link to w3c doc for xml default namespaces.
..
.. bpo: 8722
.. date: 2018-02-03-06-11-37
.. nonce: MPyVyj
.. section: Documentation
Document :meth:`__getattr__` behavior when property :meth:`get` method
raises :exc:`AttributeError`.
..
.. bpo: 32614
.. date: 2018-02-02-07-41-57
.. nonce: LSqzGw
.. section: Documentation
Modify RE examples in documentation to use raw strings to prevent
:exc:`DeprecationWarning` and add text to REGEX HOWTO to highlight the
deprecation.
..
.. bpo: 31972
.. date: 2018-01-25-14-23-12
.. nonce: w1m_8r
.. section: Documentation
Improve docstrings for ``pathlib.PurePath`` subclasses.
..
.. bpo: 17799
.. date: 2018-01-22-21-13-46
.. nonce: rdZ-Vk
.. section: Documentation
Explain real behaviour of sys.settrace and sys.setprofile and their C-API
counterparts regarding which type of events are received in each function.
Patch by Pablo Galindo Salgado.
..
.. bpo: 32517
.. date: 2018-03-09-07-05-12
.. nonce: ugc1iW
.. section: Tests
Fix failing ``test_asyncio`` on macOS 10.12.2+ due to transport of
``KqueueSelector`` loop was not being closed.
..
.. bpo: 32721
.. date: 2018-01-29-21-30-44
.. nonce: 2Bebm1
.. section: Tests
Fix test_hashlib to not fail if the _md5 module is not built.
..
.. bpo: 32252
.. date: 2017-12-11-13-31-33
.. nonce: YnFw7J
.. section: Tests
Fix faulthandler_suppress_crash_report() used to prevent core dump files
when testing crashes. getrlimit() returns zero on success.
..
.. bpo: 31518
.. date: 2017-09-19-20-48-50
.. nonce: KwTMMz
.. section: Tests
Debian Unstable has disabled TLS 1.0 and 1.1 for SSLv23_METHOD(). Change
TLS/SSL protocol of some tests to PROTOCOL_TLS or PROTOCOL_TLSv1_2 to make
them pass on Debian.
..
.. bpo: 32635
.. date: 2018-01-23-15-33-40
.. nonce: qHwIZy
.. section: Build
Fix segfault of the crypt module when libxcrypt is provided instead of
libcrypt at the system.
..
.. bpo: 33016
.. date: 2018-03-07-01-33-33
.. nonce: Z_Med0
.. section: Windows
Fix potential use of uninitialized memory in nt._getfinalpathname
..
.. bpo: 32903
.. date: 2018-02-28-11-03-24
.. nonce: 1SXY4t
.. section: Windows
Fix a memory leak in os.chdir() on Windows if the current directory is set
to a UNC path.
..
.. bpo: 31966
.. date: 2018-02-19-13-54-42
.. nonce: _Q3HPb
.. section: Windows
Fixed WindowsConsoleIO.write() for writing empty data.
..
.. bpo: 32409
.. date: 2018-02-19-10-00-57
.. nonce: nocuDg
.. section: Windows
Ensures activate.bat can handle Unicode contents.
..
.. bpo: 32457
.. date: 2018-02-19-08-54-06
.. nonce: vVP0Iz
.. section: Windows
Improves handling of denormalized executable path when launching Python.
..
.. bpo: 32370
.. date: 2018-02-10-15-38-19
.. nonce: kcKuct
.. section: Windows
Use the correct encoding for ipconfig output in the uuid module. Patch by
Segev Finer.
..
.. bpo: 29248
.. date: 2018-02-07-17-50-48
.. nonce: Xzwj-6
.. section: Windows
Fix :func:`os.readlink` on Windows, which was mistakenly treating the
``PrintNameOffset`` field of the reparse data buffer as a number of
characters instead of bytes. Patch by Craig Holmquist and SSE4.
..
.. bpo: 32588
.. date: 2018-01-18-14-56-45
.. nonce: vHww6F
.. section: Windows
Create standalone _distutils_findvs module.
..
.. bpo: 32726
.. date: 2018-03-13-21-00-20
.. nonce: Mticyn
.. section: macOS
Provide an additional, more modern macOS installer variant that supports
macOS 10.9+ systems in 64-bit mode only. Upgrade the supplied third-party
libraries to OpenSSL 1.0.2n, XZ 5.2.3, and SQLite 3.22.0. The 10.9+
installer now links with and supplies its own copy of Tcl/Tk 8.6.8.
..
.. bpo: 32984
.. date: 2018-03-05-01-29-05
.. nonce: NGjgT4
.. section: IDLE
Set ``__file__`` while running a startup file.  Like Python, IDLE optionally
runs one startup file in the Shell window before presenting the first
interactive input prompt.  For IDLE, ``-s`` runs a file named in
environmental variable  :envvar:`IDLESTARTUP` or  :envvar:`PYTHONSTARTUP`;
``-r file`` runs ``file``.  Python sets ``__file__`` to the startup file
name before running the file and unsets it before the first prompt.  IDLE
now does the same when run normally, without the ``-n`` option.
..
.. bpo: 32940
.. date: 2018-02-24-18-20-50
.. nonce: ZaJ1Rf
.. section: IDLE
Simplify and rename StringTranslatePseudoMapping in pyparse.
..
.. bpo: 32916
.. date: 2018-02-23-07-32-36
.. nonce: 4MsQ5F
.. section: IDLE
Change ``str`` to ``code`` in pyparse.
..
.. bpo: 32905
.. date: 2018-02-22-00-09-27
.. nonce: VlXj0x
.. section: IDLE
Remove unused code in pyparse module.
..
.. bpo: 32874
.. date: 2018-02-19-10-56-41
.. nonce: 6pZ9Gv
.. section: IDLE
Add tests for pyparse.
..
.. bpo: 32837
.. date: 2018-02-12-17-22-48
.. nonce: -33QPl
.. section: IDLE
Using the system and place-dependent default encoding for open() is a bad
idea for IDLE's system and location-independent files.
..
.. bpo: 32826
.. date: 2018-02-12-11-05-22
.. nonce: IxNZrk
.. section: IDLE
Add "encoding=utf-8" to open() in IDLE's test_help_about. GUI test
test_file_buttons() only looks at initial ascii-only lines, but failed on
systems where open() defaults to 'ascii' because readline() internally reads
and decodes far enough ahead to encounter a non-ascii character in
CREDITS.txt.
..
.. bpo: 32765
.. date: 2018-02-04-17-52-54
.. nonce: qm0eCu
.. section: IDLE
Update configdialog General tab docstring to add new widgets to the widget
list.
..
.. bpo: 24960
.. date: 2017-12-22-09-25-51
.. nonce: TGdAgO
.. section: Tools/Demos
2to3 and lib2to3 can now read pickled grammar files using pkgutil.get_data()
rather than probing the filesystem. This lets 2to3 and lib2to3 work when run
from a zipfile.
..
.. bpo: 32222
.. date: 2017-12-07-20-51-20
.. nonce: hPBcGT
.. section: Tools/Demos
Fix pygettext not extracting docstrings for functions with type annotated
arguments. Patch by Toby Harradine.
..
.. bpo: 29084
.. date: 2017-12-16-09-59-35
.. nonce: ZGJ-LJ
.. section: C API
Undocumented C API for OrderedDict has been excluded from the limited C API.
It was added by mistake and actually never worked in the limited C API.

.. bpo: 28532
.. date: 9778
.. nonce: KEYJny
.. release date: 2016-11-21
.. section: Core and Builtins
Show sys.version when -V option is supplied twice.
..
.. bpo: 27100
.. date: 9777
.. nonce: poVjXq
.. section: Core and Builtins
The with-statement now checks for __enter__ before it checks for __exit__.
This gives less confusing error messages when both methods are missing.
Patch by Jonathan Ellington.
..
.. bpo: 28746
.. date: 9776
.. nonce: r5MXdB
.. section: Core and Builtins
Fix the set_inheritable() file descriptor method on platforms that do not
have the ioctl FIOCLEX and FIONCLEX commands.
..
.. bpo: 26920
.. date: 9775
.. nonce: 1URwGb
.. section: Core and Builtins
Fix not getting the locale's charset upon initializing the interpreter, on
platforms that do not have langinfo.
..
.. bpo: 28648
.. date: 9774
.. nonce: z7B52W
.. section: Core and Builtins
Fixed crash in Py_DecodeLocale() in debug build on Mac OS X when decode
astral characters.  Patch by Xiang Zhang.
..
.. bpo: 19398
.. date: 9773
.. nonce: RYbEGH
.. section: Core and Builtins
Extra slash no longer added to sys.path components in case of empty
compile-time PYTHONPATH components.
..
.. bpo: 28665
.. date: 9772
.. nonce: v4nx86
.. section: Core and Builtins
Improve speed of the STORE_DEREF opcode by 40%.
..
.. bpo: 28583
.. date: 9771
.. nonce: F-QAx1
.. section: Core and Builtins
PyDict_SetDefault didn't combine split table when needed. Patch by Xiang
Zhang.
..
.. bpo: 27243
.. date: 9770
.. nonce: 61E6K5
.. section: Core and Builtins
Change PendingDeprecationWarning -> DeprecationWarning. As it was agreed in
the issue, __aiter__ returning an awaitable should result in
PendingDeprecationWarning in 3.5 and in DeprecationWarning in 3.6.
..
.. bpo: 26182
.. date: 9769
.. nonce: a8JXK2
.. section: Core and Builtins
Fix a refleak in code that raises DeprecationWarning.
..
.. bpo: 28721
.. date: 9768
.. nonce: BO9BUF
.. section: Core and Builtins
Fix asynchronous generators aclose() and athrow() to handle
StopAsyncIteration propagation properly.
..
.. bpo: 28752
.. date: 9767
.. nonce: Q-4oRE
.. section: Library
Restored the __reduce__() methods of datetime objects.
..
.. bpo: 28727
.. date: 9766
.. nonce: ubZP_b
.. section: Library
Regular expression patterns, _sre.SRE_Pattern objects created by
re.compile(), become comparable (only x==y and x!=y operators). This change
should fix the issue #18383: don't duplicate warning filters when the
warnings module is reloaded (thing usually only done in unit tests).
..
.. bpo: 20572
.. date: 9765
.. nonce: lGXaH9
.. section: Library
The subprocess.Popen.wait method's undocumented endtime parameter now raises
a DeprecationWarning.
..
.. bpo: 25659
.. date: 9764
.. nonce: lE2IlT
.. section: Library
In ctypes, prevent a crash calling the from_buffer() and from_buffer_copy()
methods on abstract classes like Array.
..
.. bpo: 19717
.. date: 9763
.. nonce: HXCAIz
.. section: Library
Makes Path.resolve() succeed on paths that do not exist. Patch by Vajrasky
Kok
..
.. bpo: 28563
.. date: 9762
.. nonce: iweEiw
.. section: Library
Fixed possible DoS and arbitrary code execution when handle plural form
selections in the gettext module.  The expression parser now supports exact
syntax supported by GNU gettext.
..
.. bpo: 28387
.. date: 9761
.. nonce: 1clJu7
.. section: Library
Fixed possible crash in _io.TextIOWrapper deallocator when the garbage
collector is invoked in other thread.  Based on patch by Sebastian Cufre.
..
.. bpo: 28600
.. date: 9760
.. nonce: wMVrjN
.. section: Library
Optimize loop.call_soon.
..
.. bpo: 28613
.. date: 9759
.. nonce: sqUPrv
.. section: Library
Fix get_event_loop() return the current loop if called from
coroutines/callbacks.
..
.. bpo: 28634
.. date: 9758
.. nonce: YlRydz
.. section: Library
Fix asyncio.isfuture() to support unittest.Mock.
..
.. bpo: 26081
.. date: 9757
.. nonce: 2Y8-a9
.. section: Library
Fix refleak in _asyncio.Future.__iter__().throw.
..
.. bpo: 28639
.. date: 9756
.. nonce: WUPo1o
.. section: Library
Fix inspect.isawaitable to always return bool Patch by Justin Mayfield.
..
.. bpo: 28652
.. date: 9755
.. nonce: f5M8FG
.. section: Library
Make loop methods reject socket kinds they do not support.
..
.. bpo: 28653
.. date: 9754
.. nonce: S5bA9i
.. section: Library
Fix a refleak in functools.lru_cache.
..
.. bpo: 28703
.. date: 9753
.. nonce: CRLTJc
.. section: Library
Fix asyncio.iscoroutinefunction to handle Mock objects.
..
.. bpo: 28704
.. date: 9752
.. nonce: EFWBII
.. section: Library
Fix create_unix_server to support Path-like objects (PEP 519).
..
.. bpo: 28720
.. date: 9751
.. nonce: Fsz-Lf
.. section: Library
Add collections.abc.AsyncGenerator.
..
.. bpo: 28513
.. date: 9750
.. nonce: L3joAz
.. section: Documentation
Documented command-line interface of zipfile.
..
.. bpo: 28666
.. date: 9749
.. nonce: RtTk-4
.. section: Tests
Now test.support.rmtree is able to remove unwritable or unreadable
directories.
..
.. bpo: 23839
.. date: 9748
.. nonce: zsT_L9
.. section: Tests
Various caches now are cleared before running every test file.
..
.. bpo: 10656
.. date: 9747
.. nonce: pR8FFU
.. section: Build
Fix out-of-tree building on AIX.  Patch by Tristan Carel and Michael
Haubenwallner.
..
.. bpo: 26359
.. date: 9746
.. nonce: CLz6qy
.. section: Build
Rename --with-optimiations to --enable-optimizations.
..
.. bpo: 28676
.. date: 9745
.. nonce: Wxf6Ds
.. section: Build
Prevent missing 'getentropy' declaration warning on macOS. Patch by Gareth
Rees.

.. bpo: 23573
.. date: 9042
.. nonce: ZpM4D-
.. release date: 2015-03-28
.. section: Core and Builtins
Increased performance of string search operations (str.find, str.index,
str.count, the in operator, str.split, str.partition) with arguments of
different kinds (UCS1, UCS2, UCS4).
..
.. bpo: 23753
.. date: 9041
.. nonce: CREjLC
.. section: Core and Builtins
Python doesn't support anymore platforms without stat() or fstat(), these
functions are always required.
..
.. bpo: 23681
.. date: 9040
.. nonce: kh02TF
.. section: Core and Builtins
The -b option now affects comparisons of bytes with int.
..
.. bpo: 23632
.. date: 9039
.. nonce: UVdIZY
.. section: Core and Builtins
Memoryviews now allow tuple indexing (including for multi-dimensional
memoryviews).
..
.. bpo: 23192
.. date: 9038
.. nonce: QKqdow
.. section: Core and Builtins
Fixed generator lambdas.  Patch by Bruno Cauet.
..
.. bpo: 23629
.. date: 9037
.. nonce: r9Mt2C
.. section: Core and Builtins
Fix the default __sizeof__ implementation for variable-sized objects.
..
.. bpo: 14260
.. date: 9036
.. nonce: b5M04V
.. section: Library
The groupindex attribute of regular expression pattern object now is
non-modifiable mapping.
..
.. bpo: 23792
.. date: 9035
.. nonce: Kfm9-f
.. section: Library
Ignore KeyboardInterrupt when the pydoc pager is active. This mimics the
behavior of the standard unix pagers, and prevents pipepager from shutting
down while the pager itself is still running.
..
.. bpo: 23775
.. date: 9034
.. nonce: xKGrSQ
.. section: Library
pprint() of OrderedDict now outputs the same representation as repr().
..
.. bpo: 23765
.. date: 9033
.. nonce: 2ta_C4
.. section: Library
Removed IsBadStringPtr calls in ctypes
..
.. bpo: 22364
.. date: 9032
.. nonce: ejtoKl
.. section: Library
Improved some re error messages using regex for hints.
..
.. bpo: 23742
.. date: 9031
.. nonce: _EkAIa
.. section: Library
ntpath.expandvars() no longer loses unbalanced single quotes.
..
.. bpo: 21717
.. date: 9030
.. nonce: pKndpx
.. section: Library
The zipfile.ZipFile.open function now supports 'x' (exclusive creation)
mode.
..
.. bpo: 21802
.. date: 9029
.. nonce: ygSM2A
.. section: Library
The reader in BufferedRWPair now is closed even when closing writer failed
in BufferedRWPair.close().
..
.. bpo: 23622
.. date: 9028
.. nonce: 9-ZRqj
.. section: Library
Unknown escapes in regular expressions that consist of ``'\'`` and ASCII
letter now raise a deprecation warning and will be forbidden in Python 3.6.
..
.. bpo: 23671
.. date: 9027
.. nonce: zWPm-a
.. section: Library
string.Template now allows specifying the "self" parameter as a keyword
argument.  string.Formatter now allows specifying the "self" and the
"format_string" parameters as keyword arguments.
..
.. bpo: 23502
.. date: 9026
.. nonce: AH20IQ
.. section: Library
The pprint module now supports mapping proxies.
..
.. bpo: 17530
.. date: 9025
.. nonce: PUp8rL
.. section: Library
pprint now wraps long bytes objects and bytearrays.
..
.. bpo: 22687
.. date: 9024
.. nonce: zEJPd9
.. section: Library
Fixed some corner cases in breaking words in tetxtwrap. Got rid of quadratic
complexity in breaking long words.
..
.. bpo: 4727
.. date: 9023
.. nonce: iDQSpi
.. section: Library
The copy module now uses pickle protocol 4 (PEP 3154) and supports copying
of instances of classes whose __new__ method takes keyword-only arguments.
..
.. bpo: 23491
.. date: 9022
.. nonce: P_WKrt
.. section: Library
Added a zipapp module to support creating executable zip file archives of
Python code. Registered ".pyz" and ".pyzw" extensions on Windows for these
archives (PEP 441).
..
.. bpo: 23657
.. date: 9021
.. nonce: y1OaV-
.. section: Library
Avoid explicit checks for str in zipapp, adding support for pathlib.Path
objects as arguments.
..
.. bpo: 23688
.. date: 9020
.. nonce: d6LVy3
.. section: Library
Added support of arbitrary bytes-like objects and avoided unnecessary
copying of memoryview in gzip.GzipFile.write(). Original patch by Wolfgang
Maier.
..
.. bpo: 23252
.. date: 9019
.. nonce: Goi18g
.. section: Library
Added support for writing ZIP files to unseekable streams.
..
.. bpo: 23647
.. date: 9018
.. nonce: pX2qrx
.. section: Library
Increase imaplib's MAXLINE to accommodate modern mailbox sizes.
..
.. bpo: 23539
.. date: 9017
.. nonce: 5BVUim
.. section: Library
If body is None, http.client.HTTPConnection.request now sets Content-Length
to 0 for PUT, POST, and PATCH headers to avoid 411 errors from some web
servers.
..
.. bpo: 22351
.. date: 9016
.. nonce: agB8Y3
.. section: Library
The nntplib.NNTP constructor no longer leaves the connection and socket open
until the garbage collector cleans them up.  Patch by Martin Panter.
..
.. bpo: 23704
.. date: 9015
.. nonce: LTyyxL
.. section: Library
collections.deque() objects now support methods for index(), insert(), and
copy().  This allows deques to be registered as a MutableSequence and it
improves their substitutability for lists.
..
.. bpo: 23715
.. date: 9014
.. nonce: Yap3tU
.. section: Library
:func:`signal.sigwaitinfo` and :func:`signal.sigtimedwait` are now retried
when interrupted by a signal not in the *sigset* parameter, if the signal
handler does not raise an exception. signal.sigtimedwait() recomputes the
timeout with a monotonic clock when it is retried.
..
.. bpo: 23001
.. date: 9013
.. nonce: YSFnam
.. section: Library
Few functions in modules mmap, ossaudiodev, socket, ssl, and codecs, that
accepted only read-only bytes-like object now accept writable bytes-like
object too.
..
.. bpo: 23646
.. date: 9012
.. nonce: Tljc1S
.. section: Library
If time.sleep() is interrupted by a signal, the sleep is now retried with
the recomputed delay, except if the signal handler raises an exception (PEP
475).
..
.. bpo: 23136
.. date: 9011
.. nonce: 1bnpnb
.. section: Library
_strptime now uniformly handles all days in week 0, including Dec 30 of
previous year.  Based on patch by Jim Carroll.
..
.. bpo: 23700
.. date: 9010
.. nonce: VfnWwi
.. section: Library
Iterator of NamedTemporaryFile now keeps a reference to NamedTemporaryFile
instance.  Patch by Bohuslav Kabrda.
..
.. bpo: 22903
.. date: 9009
.. nonce: 2GjTHY
.. section: Library
The fake test case created by unittest.loader when it fails importing a test
module is now picklable.
..
.. bpo: 22181
.. date: 9008
.. nonce: 7mnxea
.. section: Library
On Linux, os.urandom() now uses the new getrandom() syscall if available,
syscall introduced in the Linux kernel 3.17. It is more reliable and more
secure, because it avoids the need of a file descriptor and waits until the
kernel has enough entropy.
..
.. bpo: 2211
.. date: 9007
.. nonce: 17Iz5U
.. section: Library
Updated the implementation of the http.cookies.Morsel class. Setting
attributes key, value and coded_value directly now is deprecated. update()
and setdefault() now transform and check keys.  Comparing for equality now
takes into account attributes key, value and coded_value. copy() now returns
a Morsel, not a dict.  repr() now contains all attributes. Optimized
checking keys and quoting values.  Added new tests. Original patch by Demian
Brecht.
..
.. bpo: 18983
.. date: 9006
.. nonce: vF4i2S
.. section: Library
Allow selection of output units in timeit. Patch by Julian Gindi.
..
.. bpo: 23631
.. date: 9005
.. nonce: GfSqNI
.. section: Library
Fix traceback.format_list when a traceback has been mutated.
..
.. bpo: 23568
.. date: 9004
.. nonce: ffzJc7
.. section: Library
Add rdivmod support to MagicMock() objects. Patch by Håkan Lövdahl.
..
.. bpo: 2052
.. date: 9003
.. nonce: ujNgna
.. section: Library
Add charset parameter to HtmlDiff.make_file().
..
.. bpo: 23668
.. date: 9002
.. nonce: nF_jnN
.. section: Library
Support os.truncate and os.ftruncate on Windows.
..
.. bpo: 23138
.. date: 9001
.. nonce: 4vMoMZ
.. section: Library
Fixed parsing cookies with absent keys or values in cookiejar. Patch by
Demian Brecht.
..
.. bpo: 23051
.. date: 9000
.. nonce: Vi5tCZ
.. section: Library
multiprocessing.Pool methods imap() and imap_unordered() now handle
exceptions raised by an iterator.  Patch by Alon Diamant and Davin Potts.
..
.. bpo: 23581
.. date: 8999
.. nonce: D4Lknl
.. section: Library
Add matmul support to MagicMock. Patch by Håkan Lövdahl.
..
.. bpo: 23566
.. date: 8998
.. nonce: F6LSyk
.. section: Library
enable(), register(), dump_traceback() and dump_traceback_later() functions
of faulthandler now accept file descriptors. Patch by Wei Wu.
..
.. bpo: 22928
.. date: 8997
.. nonce: q2TmY0
.. section: Library
Disabled HTTP header injections in http.client. Original patch by Demian
Brecht.
..
.. bpo: 23615
.. date: 8996
.. nonce: 5Kx9k5
.. section: Library
Modules bz2, tarfile and tokenize now can be reloaded with imp.reload().
Patch by Thomas Kluyver.
..
.. bpo: 23605
.. date: 8995
.. nonce: JUOA_X
.. section: Library
os.walk() now calls os.scandir() instead of os.listdir(). The usage of
os.scandir() reduces the number of calls to os.stat(). Initial patch written
by Ben Hoyt.
..
.. bpo: 23585
.. date: 8994
.. nonce: DTIIoI
.. section: Build
make patchcheck will ensure the interpreter is built.
..
.. bpo: 23583
.. date: 8993
.. nonce: bY8AbM
.. section: Tests
Added tests for standard IO streams in IDLE.
..
.. bpo: 22289
.. date: 8992
.. nonce: ybGcC-
.. section: Tests
Prevent test_urllib2net failures due to ftp connection timeout.
..
.. bpo: 22826
.. date: 8991
.. nonce: 3bcoDL
.. section: Tools/Demos
The result of open() in Tools/freeze/bkfile.py is now better compatible with
regular files (in particular it now supports the context management
protocol).

.. bpo: 27704
.. date: 9455
.. nonce: RUxzHf
.. release date: 2016-08-15
.. section: Core and Builtins
Optimized creating bytes and bytearray from byte-like objects and iterables.
Speed up to 3 times for short objects.  Original patch by Naoki Inada.
..
.. bpo: 26823
.. date: 9454
.. nonce: UWORiU
.. section: Core and Builtins
Large sections of repeated lines in tracebacks are now abbreviated as
"[Previous line repeated {count} more times]" by the builtin traceback
rendering. Patch by Emanuel Barry.
..
.. bpo: 27574
.. date: 9453
.. nonce: q73Tss
.. section: Core and Builtins
Decreased an overhead of parsing keyword arguments in functions implemented
with using Argument Clinic.
..
.. bpo: 22557
.. date: 9452
.. nonce: Hta2Rz
.. section: Core and Builtins
Now importing already imported modules is up to 2.5 times faster.
..
.. bpo: 17596
.. date: 9451
.. nonce: XgbA9V
.. section: Core and Builtins
Include <wincrypt.h> to help with Min GW building.
..
.. bpo: 17599
.. date: 9450
.. nonce: noy7o1
.. section: Core and Builtins
On Windows, rename the privately defined REPARSE_DATA_BUFFER structure to
avoid conflicting with the definition from Min GW.
..
.. bpo: 27507
.. date: 9449
.. nonce: 3pX0Be
.. section: Core and Builtins
Add integer overflow check in bytearray.extend().  Patch by Xiang Zhang.
..
.. bpo: 27581
.. date: 9448
.. nonce: KezjNt
.. section: Core and Builtins
Don't rely on wrapping for overflow check in PySequence_Tuple().  Patch by
Xiang Zhang.
..
.. bpo: 1621
.. date: 9447
.. nonce: _FZWTr
.. section: Core and Builtins
Avoid signed integer overflow in list and tuple operations. Patch by Xiang
Zhang.
..
.. bpo: 27419
.. date: 9446
.. nonce: YaGodL
.. section: Core and Builtins
Standard __import__() no longer look up "__import__" in globals or builtins
for importing submodules or "from import".  Fixed a crash if raise a warning
about unabling to resolve package from __spec__ or __package__.
..
.. bpo: 27083
.. date: 9445
.. nonce: F4ZT1C
.. section: Core and Builtins
Respect the PYTHONCASEOK environment variable under Windows.
..
.. bpo: 27514
.. date: 9444
.. nonce: NLbwPG
.. section: Core and Builtins
Make having too many statically nested blocks a SyntaxError instead of
SystemError.
..
.. bpo: 27366
.. date: 9443
.. nonce: VrInsj
.. section: Core and Builtins
Implemented :pep:`487` (Simpler customization of class creation). Upon
subclassing, the __init_subclass__ classmethod is called on the base class.
Descriptors are initialized with __set_name__ after class creation.
..
.. bpo: 26027
.. date: 9442
.. nonce: nfVMKM
.. section: Library
Add :pep:`519`/__fspath__() support to the os and os.path modules. Includes
code from Jelle Zijlstra. (See also: bpo-27524)
..
.. bpo: 27598
.. date: 9441
.. nonce: y7PtEV
.. section: Library
Add Collections to collections.abc. Patch by Ivan Levkivskyi, docs by Neil
Girdhar.
..
.. bpo: 25958
.. date: 9440
.. nonce: X-V4U1
.. section: Library
Support "anti-registration" of special methods from various ABCs, like
__hash__, __iter__ or __len__.  All these (and several more) can be set to
None in an implementation class and the behavior will be as if the method is
not defined at all. (Previously, this mechanism existed only for __hash__,
to make mutable classes unhashable.)  Code contributed by Andrew Barnert and
Ivan Levkivskyi.
..
.. bpo: 16764
.. date: 9439
.. nonce: cPbNjL
.. section: Library
Support keyword arguments to zlib.decompress().  Patch by Xiang Zhang.
..
.. bpo: 27736
.. date: 9438
.. nonce: 8kMhpQ
.. section: Library
Prevent segfault after interpreter re-initialization due to ref count
problem introduced in code for issue #27038 in 3.6.0a3. Patch by Xiang
Zhang.
..
.. bpo: 25628
.. date: 9437
.. nonce: UcQnHF
.. section: Library
The *verbose* and *rename* parameters for collections.namedtuple are now
keyword-only.
..
.. bpo: 12345
.. date: 9436
.. nonce: nbAEM8
.. section: Library
Add mathematical constant tau to math and cmath. See also :pep:`628`.
..
.. bpo: 26823
.. date: 9435
.. nonce: HcO8tR
.. section: Library
traceback.StackSummary.format now abbreviates large sections of repeated
lines as "[Previous line repeated {count} more times]" (this change then
further affects other traceback display operations in the module). Patch by
Emanuel Barry.
..
.. bpo: 27664
.. date: 9434
.. nonce: 6DJPxw
.. section: Library
Add to concurrent.futures.thread.ThreadPoolExecutor() the ability to specify
a thread name prefix.
..
.. bpo: 27181
.. date: 9433
.. nonce: 8aw9TZ
.. section: Library
Add geometric_mean and harmonic_mean to statistics module.
..
.. bpo: 27573
.. date: 9432
.. nonce: B7XhTs
.. section: Library
code.interact now prints an message when exiting.
..
.. bpo: 6422
.. date: 9431
.. nonce: iBSc45
.. section: Library
Add autorange method to timeit.Timer objects.
..
.. bpo: 27773
.. date: 9430
.. nonce: hMSSeX
.. section: Library
Correct some memory management errors server_hostname in _ssl.wrap_socket().
..
.. bpo: 26750
.. date: 9429
.. nonce: OQn3fr
.. section: Library
unittest.mock.create_autospec() now works properly for subclasses of
property() and other data descriptors.  Removes the never publicly used,
never documented unittest.mock.DescriptorTypes tuple.
..
.. bpo: 26754
.. date: 9428
.. nonce: XZqomf
.. section: Library
Undocumented support of general bytes-like objects as path in compile() and
similar functions is now deprecated.
..
.. bpo: 26800
.. date: 9427
.. nonce: QDcK8u
.. section: Library
Undocumented support of general bytes-like objects as paths in os functions
is now deprecated.
..
.. bpo: 26981
.. date: 9426
.. nonce: yhNTCf
.. section: Library
Add _order_ compatibility shim to enum.Enum for Python 2/3 code bases.
..
.. bpo: 27661
.. date: 9425
.. nonce: 3JZckO
.. section: Library
Added tzinfo keyword argument to datetime.combine.
..
.. bpo: 0
.. date: 9424
.. nonce: Ny9oPv
.. section: Library
In the curses module, raise an error if window.getstr() or window.instr() is
passed a negative value.
..
.. bpo: 27783
.. date: 9423
.. nonce: cR1jXH
.. section: Library
Fix possible usage of uninitialized memory in operator.methodcaller.
..
.. bpo: 27774
.. date: 9422
.. nonce: FDcik1
.. section: Library
Fix possible Py_DECREF on unowned object in _sre.
..
.. bpo: 27760
.. date: 9421
.. nonce: gxMjp4
.. section: Library
Fix possible integer overflow in binascii.b2a_qp.
..
.. bpo: 27758
.. date: 9420
.. nonce: 0NRV03
.. section: Library
Fix possible integer overflow in the _csv module for large record lengths.
..
.. bpo: 27568
.. date: 9419
.. nonce: OnuO9s
.. section: Library
Prevent HTTPoxy attack (:cve:`2016-1000110`). Ignore the HTTP_PROXY variable
when REQUEST_METHOD environment is set, which indicates that the script is
in CGI mode.
..
.. bpo: 7063
.. date: 9418
.. nonce: nXsVKB
.. section: Library
Remove dead code from the "array" module's slice handling. Patch by Chuck.
..
.. bpo: 27656
.. date: 9417
.. nonce: joTscM
.. section: Library
Do not assume sched.h defines any SCHED_* constants.
..
.. bpo: 27130
.. date: 9416
.. nonce: SUxwXZ
.. section: Library
In the "zlib" module, fix handling of large buffers (typically 4 GiB) when
compressing and decompressing.  Previously, inputs were limited to 4 GiB,
and compression and decompression operations did not properly handle results
of 4 GiB.
..
.. bpo: 24773
.. date: 9415
.. nonce: IDW05R
.. section: Library
Implemented :pep:`495` (Local Time Disambiguation).
..
.. bpo: 0
.. date: 9414
.. nonce: lOkwM8
.. section: Library
Expose the EPOLLEXCLUSIVE constant (when it is defined) in the select
module.
..
.. bpo: 27567
.. date: 9413
.. nonce: bYOgyw
.. section: Library
Expose the EPOLLRDHUP and POLLRDHUP constants in the select module.
..
.. bpo: 1621
.. date: 9412
.. nonce: 0nclmI
.. section: Library
Avoid signed int negation overflow in the "audioop" module.
..
.. bpo: 27533
.. date: 9411
.. nonce: iDmKzV
.. section: Library
Release GIL in nt._isdir
..
.. bpo: 17711
.. date: 9410
.. nonce: 47AILJ
.. section: Library
Fixed unpickling by the persistent ID with protocol 0. Original patch by
Alexandre Vassalotti.
..
.. bpo: 27522
.. date: 9409
.. nonce: 8vVz_t
.. section: Library
Avoid an unintentional reference cycle in email.feedparser.
..
.. bpo: 27512
.. date: 9408
.. nonce: FaGwup
.. section: Library
Fix a segfault when os.fspath() called an __fspath__() method that raised an
exception. Patch by Xiang Zhang.
..
.. bpo: 27714
.. date: 9407
.. nonce: bUEDsI
.. section: IDLE
text_textview and test_autocomplete now pass when re-run in the same
process.  This occurs when test_idle fails when run with the -w option but
without -jn.  Fix warning from test_config.
..
.. bpo: 27621
.. date: 9406
.. nonce: BcpOPU
.. section: IDLE
Put query response validation error messages in the query box itself instead
of in a separate messagebox.  Redo tests to match. Add Mac OSX refinements.
Original patch by Mark Roseman.
..
.. bpo: 27620
.. date: 9405
.. nonce: TXRR6x
.. section: IDLE
Escape key now closes Query box as cancelled.
..
.. bpo: 27609
.. date: 9404
.. nonce: MbTuKa
.. section: IDLE
IDLE: tab after initial whitespace should tab, not autocomplete. This fixes
problem with writing docstrings at least twice indented.
..
.. bpo: 27609
.. date: 9403
.. nonce: OBYgv_
.. section: IDLE
Explicitly return None when there are also non-None returns. In a few cases,
reverse a condition and eliminate a return.
..
.. bpo: 25507
.. date: 9402
.. nonce: lxf68d
.. section: IDLE
IDLE no longer runs buggy code because of its tkinter imports. Users must
include the same imports required to run directly in Python.
..
.. bpo: 27173
.. date: 9401
.. nonce: M-fYaV
.. section: IDLE
Add 'IDLE Modern Unix' to the built-in key sets. Make the default key set
depend on the platform. Add tests for the changes to the config module.
..
.. bpo: 27452
.. date: 9400
.. nonce: RtWnyR
.. section: IDLE
add line counter and crc to IDLE configHandler test dump.
..
.. bpo: 25805
.. date: 9399
.. nonce: 9SVxXQ
.. section: Tests
Skip a test in test_pkgutil as needed that doesn't work when ``__name__ ==
__main__``. Patch by SilentGhost.
..
.. bpo: 27472
.. date: 9398
.. nonce: NS3L93
.. section: Tests
Add test.support.unix_shell as the path to the default shell.
..
.. bpo: 27369
.. date: 9397
.. nonce: LG7U2D
.. section: Tests
In test_pyexpat, avoid testing an error message detail that changed in Expat
2.2.0.
..
.. bpo: 27594
.. date: 9396
.. nonce: w3F57B
.. section: Tests
Prevent assertion error when running test_ast with coverage enabled: ensure
code object has a valid first line number. Patch suggested by Ivan
Levkivskyi.
..
.. bpo: 27647
.. date: 9395
.. nonce: -1HUR6
.. section: Windows
Update bundled Tcl/Tk to 8.6.6.
..
.. bpo: 27610
.. date: 9394
.. nonce: O0o0mB
.. section: Windows
Adds :pep:`514` metadata to Windows installer
..
.. bpo: 27469
.. date: 9393
.. nonce: 0GwDkX
.. section: Windows
Adds a shell extension to the launcher so that drag and drop works
correctly.
..
.. bpo: 27309
.. date: 9392
.. nonce: chiOo6
.. section: Windows
Enables proper Windows styles in python[w].exe manifest.
..
.. bpo: 27713
.. date: 9391
.. nonce: _3DgXG
.. section: Build
Suppress spurious build warnings when updating importlib's bootstrap files.
Patch by Xiang Zhang
..
.. bpo: 25825
.. date: 9390
.. nonce: MLbdVU
.. section: Build
Correct the references to Modules/python.exp, which is required on AIX.  The
references were accidentally changed in 3.5.0a1.
..
.. bpo: 27453
.. date: 9389
.. nonce: Pb5DBi
.. section: Build
CPP invocation in configure must use CPPFLAGS. Patch by Chi Hsuan Yen.
..
.. bpo: 27641
.. date: 9388
.. nonce: eGzgCk
.. section: Build
The configure script now inserts comments into the makefile to prevent the
pgen and _freeze_importlib executables from being cross-compiled.
..
.. bpo: 26662
.. date: 9387
.. nonce: XkwRxM
.. section: Build
Set PYTHON_FOR_GEN in configure as the Python program to be used for file
generation during the build.
..
.. bpo: 10910
.. date: 9386
.. nonce: ZdRayb
.. section: Build
Avoid C++ compilation errors on FreeBSD and OS X. Also update FreedBSD
version checks for the original ctype UTF-8 workaround.

.. bpo: 33363
.. date: 2018-04-26-22-48-28
.. nonce: 8RCnN2
.. release date: 2018-05-02
.. section: Core and Builtins
Raise a SyntaxError for ``async with`` and ``async for`` statements outside
of async functions.
..
.. bpo: 33128
.. date: 2018-04-24-22-31-04
.. nonce: g2yLuf
.. section: Core and Builtins
Fix a bug that causes PathFinder to appear twice on sys.meta_path. Patch by
Pablo Galindo Salgado.
..
.. bpo: 33312
.. date: 2018-04-19-08-30-07
.. nonce: mDe2iL
.. section: Core and Builtins
Fixed clang ubsan (undefined behavior sanitizer) warnings in dictobject.c by
adjusting how the internal struct _dictkeysobject shared keys structure is
declared.
..
.. bpo: 33231
.. date: 2018-04-05-22-20-44
.. nonce: 3Jmo0q
.. section: Core and Builtins
Fix potential memory leak in ``normalizestring()``.
..
.. bpo: 33205
.. date: 2018-04-03-00-58-41
.. nonce: lk2F3r
.. section: Core and Builtins
Change dict growth function from
``round_up_to_power_2(used*2+hashtable_size/2)`` to
``round_up_to_power_2(used*3)``.  Previously, dict is shrunk only when
``used == 0``. Now dict has more chance to be shrunk.
..
.. bpo: 29922
.. date: 2018-04-03-00-30-25
.. nonce: CdLuMl
.. section: Core and Builtins
Improved error messages in 'async with' when ``__aenter__()`` or
``__aexit__()`` return non-awaitable object.
..
.. bpo: 33199
.. date: 2018-04-02-09-32-40
.. nonce: TPnxQu
.. section: Core and Builtins
Fix ``ma_version_tag`` in dict implementation is uninitialized when copying
from key-sharing dict.
..
.. bpo: 33281
.. date: 2018-05-01-22-35-50
.. nonce: d4jOt4
.. section: Library
Fix ctypes.util.find_library regression on macOS.
..
.. bpo: 33383
.. date: 2018-04-29-11-15-38
.. nonce: g32YWn
.. section: Library
Fixed crash in the get() method of the :mod:`dbm.ndbm` database object when
it is called with a single argument.
..
.. bpo: 33329
.. date: 2018-04-23-13-21-39
.. nonce: lQ-Eod
.. section: Library
Fix multiprocessing regression on newer glibcs
..
.. bpo: 991266
.. date: 2018-04-21-00-24-08
.. nonce: h93TP_
.. section: Library
Fix quoting of the ``Comment`` attribute of
:class:`http.cookies.SimpleCookie`.
..
.. bpo: 33131
.. date: 2018-04-20-10-43-17
.. nonce: L2E977
.. section: Library
Upgrade bundled version of pip to 10.0.1.
..
.. bpo: 33308
.. date: 2018-04-18-19-12-25
.. nonce: fW75xi
.. section: Library
Fixed a crash in the :mod:`parser` module when converting an ST object to a
tree of tuples or lists with ``line_info=False`` and ``col_info=True``.
..
.. bpo: 33266
.. date: 2018-04-16-15-59-21
.. nonce: w2PAm-
.. section: Library
lib2to3 now recognizes ``rf'...'`` strings.
..
.. bpo: 11594
.. date: 2018-04-16-08-42-03
.. nonce: QLo4vv
.. section: Library
Ensure line-endings are respected when using lib2to3.
..
.. bpo: 33254
.. date: 2018-04-13-15-14-47
.. nonce: DS4KFK
.. section: Library
Have :func:`importlib.resources.contents` and
:meth:`!importlib.abc.ResourceReader.contents` return an :term:`iterable`
instead of an :term:`iterator`.
..
.. bpo: 33256
.. date: 2018-04-10-20-57-14
.. nonce: ndHkqu
.. section: Library
Fix display of ``<module>`` call in the html produced by ``cgitb.html()``.
Patch by Stéphane Blondon.
..
.. bpo: 33185
.. date: 2018-04-08-22-54-07
.. nonce: Id-Ba9
.. section: Library
Fixed regression when running pydoc with the :option:`-m` switch. (The
regression was introduced in 3.7.0b3 by the resolution of :issue:`33053`)
This fix also changed pydoc to add ``os.getcwd()`` to :data:`sys.path` when
necessary, rather than adding ``"."``.
..
.. bpo: 33169
.. date: 2018-04-06-14-56-26
.. nonce: ByhDqb
.. section: Library
Delete entries of ``None`` in :data:`sys.path_importer_cache` when
:meth:`importlib.machinery.invalidate_caches` is called.
..
.. bpo: 33217
.. date: 2018-04-05-13-36-09
.. nonce: FfOKDI
.. section: Library
Deprecate looking up non-Enum objects in Enum classes and Enum members (will
raise :exc:`TypeError` in 3.8+).
..
.. bpo: 33203
.. date: 2018-04-05-11-09-45
.. nonce: Hje9Py
.. section: Library
``random.Random.choice()`` now raises ``IndexError`` for empty sequences
consistently even when called from subclasses without a ``getrandbits()``
implementation.
..
.. bpo: 33224
.. date: 2018-04-04-23-41-30
.. nonce: pyR0jB
.. section: Library
Update difflib.mdiff() for :pep:`479`.  Convert an uncaught StopIteration in a
generator into a return-statement.
..
.. bpo: 33209
.. date: 2018-04-03-10-37-13
.. nonce: 9sGWE_
.. section: Library
End framing at the end of C implementation of :func:`pickle.Pickler.dump`.
..
.. bpo: 20104
.. date: 2018-04-01-19-21-04
.. nonce: -AKcGa
.. section: Library
Improved error handling and fixed a reference leak in
:func:`os.posix_spawn`.
..
.. bpo: 33175
.. date: 2018-03-29-04-32-25
.. nonce: _zs1yM
.. section: Library
In dataclasses, Field.__set_name__ now looks up the __set_name__ special
method on the class, not the instance, of the default value.
..
.. bpo: 33097
.. date: 2018-03-18-16-48-23
.. nonce: Yl4gI2
.. section: Library
Raise RuntimeError when ``executor.submit`` is called during interpreter
shutdown.
..
.. bpo: 31908
.. date: 2017-10-31
.. nonce: g4xh8x
.. section: Library
Fix output of cover files for ``trace`` module command-line tool. Previously
emitted cover files only when ``--missing`` option was used. Patch by
Michael Selik.
..
.. bpo: 33378
.. date: 2018-04-29-04-02-18
.. nonce: -anAHN
.. section: Documentation
Add Korean language switcher for https://docs.python.org/3/
..
.. bpo: 33276
.. date: 2018-04-20-14-09-36
.. nonce: rA1z_3
.. section: Documentation
Clarify that the ``__path__`` attribute on modules cannot be just any value.
..
.. bpo: 33201
.. date: 2018-04-01-21-03-41
.. nonce: aa8Lkl
.. section: Documentation
Modernize documentation for writing C extension types.
..
.. bpo: 33195
.. date: 2018-04-01-14-30-36
.. nonce: dRS-XX
.. section: Documentation
Deprecate ``Py_UNICODE`` usage in ``c-api/arg`` document. ``Py_UNICODE``
related APIs are deprecated since Python 3.3, but it is missed in the
document.
..
.. bpo: 8243
.. date: 2018-01-13-20-30-53
.. nonce: s98r28
.. section: Documentation
Add a note about curses.addch and curses.addstr exception behavior when
writing outside a window, or pad.
..
.. bpo: 32337
.. date: 2017-12-22-17-29-37
.. nonce: eZe-ID
.. section: Documentation
Update documentation related with ``dict`` order.
..
.. bpo: 33358
.. date: 2018-04-27-11-46-35
.. nonce: _OcR59
.. section: Tests
Fix ``test_embed.test_pre_initialization_sys_options()`` when the
interpreter is built with ``--enable-shared``.
..
.. bpo: 33394
.. date: 2018-04-30-17-36-46
.. nonce: _Vdi4t
.. section: Build
Enable the verbose build for extension modules, when GNU make is passed
macros on the command line.
..
.. bpo: 33393
.. date: 2018-04-30-17-19-37
.. nonce: HkVCqI
.. section: Build
Update config.guess and config.sub files.
..
.. bpo: 33377
.. date: 2018-04-30-16-53-00
.. nonce: QBh6vP
.. section: Build
Add new triplets for mips r6 and riscv variants (used in extension
suffixes).
..
.. bpo: 32232
.. date: 2018-04-17-00-38-19
.. nonce: o7G_UO
.. section: Build
By default, modules configured in ``Modules/Setup`` are no longer built with
``-DPy_BUILD_CORE``. Instead, modules that specifically need that preprocessor
definition include it in their individual entries.
..
.. bpo: 33182
.. date: 2018-03-30-14-55-48
.. nonce: CePczb
.. section: Build
The embedding tests can once again be built with clang 6.0
..
.. bpo: 33184
.. date: 2018-04-13-11-28-55
.. nonce: 7YhqQE
.. section: Windows
Update Windows installer to use OpenSSL 1.1.0h.
..
.. bpo: 33184
.. date: 2018-04-07-00-51-34
.. nonce: 3j208P
.. section: macOS
Update macOS installer build to use OpenSSL 1.1.0h.
..
.. bpo: 21474
.. date: 2018-04-29-16-13-02
.. nonce: bglg-F
.. section: IDLE
Update word/identifier definition from ascii to unicode. In text and entry
boxes, this affects selection by double-click, movement left/right by
control-left/right, and deletion left/right by control-BACKSPACE/DEL.
..
.. bpo: 33204
.. date: 2018-04-02-00-28-13
.. nonce: NBsuIv
.. section: IDLE
IDLE: consistently color invalid string prefixes. A 'u' string prefix cannot
be paired with either 'r' or 'f'. Consistently color as much of the prefix,
starting at the right, as is valid. Revise and extend colorizer test.
..
.. bpo: 33189
.. date: 2018-04-03-18-10-00
.. nonce: QrXR00
.. section: Tools/Demos
:program:`pygettext.py` now recognizes only literal strings as docstrings
and translatable strings, and rejects bytes literals and f-string
expressions.
..
.. bpo: 31920
.. date: 2018-03-26-18-54-24
.. nonce: u_WKsT
.. section: Tools/Demos
Fixed handling directories as arguments in the ``pygettext`` script. Based
on patch by Oleg Krasnikov.
..
.. bpo: 29673
.. date: 2018-03-16-17-25-05
.. nonce: m8QtaW
.. section: Tools/Demos
Fix pystackv and pystack gdbinit macros.
..
.. bpo: 31583
.. date: 2017-09-26-10-11-21
.. nonce: TM90_H
.. section: Tools/Demos
Fix 2to3 for using with --add-suffix option but without --output-dir option
for relative path to files in current directory.

.. bpo: 39184
.. date: 2020-02-07-23-54-18
.. nonce: v-ue-v
.. release date: 2020-02-25
.. section: Security
Add audit events to functions in ``fcntl``, ``msvcrt``, ``os``, ``resource``,
``shutil``, ``signal`` and ``syslog``.
..
.. bpo: 39401
.. date: 2020-01-28-20-54-09
.. nonce: he7h_A
.. section: Security
Avoid unsafe DLL load at startup on Windows 7 and earlier.
..
.. bpo: 39184
.. date: 2020-01-07-00-42-08
.. nonce: fe7NgK
.. section: Security
Add audit events to command execution functions in os and pty modules.
..
.. bpo: 39382
.. date: 2020-02-18-01-40-13
.. nonce: OLSJu9
.. section: Core and Builtins
Fix a use-after-free in the single inheritance path of ``issubclass()``,
when the ``__bases__`` of an object has a single reference, and so does its
first item. Patch by Yonatan Goldschmidt.
..
.. bpo: 39573
.. date: 2020-02-14-10-08-53
.. nonce: BIIX2M
.. section: Core and Builtins
Update clinic tool to use :c:func:`Py_IS_TYPE`. Patch by Donghee Na.
..
.. bpo: 39619
.. date: 2020-02-13-07-35-00
.. nonce: inb_master_chroot
.. section: Core and Builtins
Enable use of :func:`os.chroot` on HP-UX systems.
..
.. bpo: 39573
.. date: 2020-02-13-01-30-22
.. nonce: uTFj1m
.. section: Core and Builtins
Add :c:func:`Py_IS_TYPE` static inline function to check whether the object
*o* type is *type*.
..
.. bpo: 39606
.. date: 2020-02-11-23-59-07
.. nonce: a72Sxc
.. section: Core and Builtins
Fix regression caused by fix for bpo-39386, that prevented calling
``aclose`` on an async generator that had already been closed or exhausted.
..
.. bpo: 39579
.. date: 2020-02-07-15-18-35
.. nonce: itNmC0
.. section: Core and Builtins
Change the ending column offset of ``Attribute`` nodes constructed in
``ast_for_dotted_name`` to point at the end of the current node and not at the
end of the last ``NAME`` node.
..
.. bpo: 1635741
.. date: 2020-02-07-12-57-40
.. nonce: ySW6gq
.. section: Core and Builtins
Port _crypt extension module to multiphase initialization (:pep:`489`).
..
.. bpo: 1635741
.. date: 2020-02-06-09-00-35
.. nonce: oaxe1j
.. section: Core and Builtins
Port _contextvars extension module to multiphase initialization
(:pep:`489`).
..
.. bpo: 39510
.. date: 2020-02-04-10-27-41
.. nonce: PMIh-f
.. section: Core and Builtins
Fix segfault in ``readinto()`` method on closed BufferedReader.
..
.. bpo: 39502
.. date: 2020-01-30-14-36-31
.. nonce: IJu0rl
.. section: Core and Builtins
Fix :func:`time.localtime` on 64-bit AIX  to support years before 1902 and
after 2038. Patch by M Felt.
..
.. bpo: 39492
.. date: 2020-01-30-01-14-42
.. nonce: eTuy0F
.. section: Core and Builtins
Fix a reference cycle in the C Pickler that was preventing the garbage
collection of deleted, pickled objects.
..
.. bpo: 39453
.. date: 2020-01-25-23-51-17
.. nonce: xCOkYk
.. section: Core and Builtins
Fixed a possible crash in :meth:`list.__contains__` when a list is changed
during comparing items. Patch by Donghee Na.
..
.. bpo: 39434
.. date: 2020-01-24-01-07-04
.. nonce: S5ehj9
.. section: Core and Builtins
:term:`floor division` of float operation now has a better performance. Also
the message of :exc:`ZeroDivisionError` for this operation is updated. Patch
by Donghee Na.
..
.. bpo: 1635741
.. date: 2020-01-19-11-06-30
.. nonce: 0mjsfm
.. section: Core and Builtins
Port _codecs extension module to multiphase initialization (:pep:`489`).
..
.. bpo: 1635741
.. date: 2020-01-18-11-06-28
.. nonce: OKROOt
.. section: Core and Builtins
Port _bz2 extension module to multiphase initialization (:pep:`489`).
..
.. bpo: 1635741
.. date: 2020-01-16-12-00-04
.. nonce: fuqoBG
.. section: Core and Builtins
Port _abc extension module to multiphase initialization (:pep:`489`).
..
.. bpo: 39320
.. date: 2020-01-15-15-50-22
.. nonce: oWARyk
.. section: Core and Builtins
Replace two complex bytecodes for building dicts with two simpler ones. The
new bytecodes ``DICT_MERGE`` and ``DICT_UPDATE`` have been added The old
bytecodes ``BUILD_MAP_UNPACK`` and ``BUILD_MAP_UNPACK_WITH_CALL`` have been
removed.
..
.. bpo: 39219
.. date: 2020-01-05-13-36-08
.. nonce: uHtKd4
.. section: Core and Builtins
Syntax errors raised in the tokenizer now always set correct "text" and
"offset" attributes.
..
.. bpo: 36051
.. date: 2019-12-30-15-56-07
.. nonce: imaVlq
.. section: Core and Builtins
Drop the GIL during large ``bytes.join`` operations. Patch by Bruce Merry.
..
.. bpo: 38960
.. date: 2019-12-03-16-41-22
.. nonce: kvoFM0
.. section: Core and Builtins
Fix DTrace build issues on FreeBSD. Patch by David Carlier.
..
.. bpo: 37207
.. date: 2019-06-09-10-54-31
.. nonce: bLjgLR
.. section: Core and Builtins
Speed up calls to ``range()`` by about 30%, by using the PEP 590
``vectorcall`` calling convention. Patch by Mark Shannon.
..
.. bpo: 36144
.. date: 2019-03-02-23-03-34
.. nonce: LRl4LS
.. section: Core and Builtins
:class:`dict` (and :class:`collections.UserDict`) objects now support PEP
584's merge (``|``) and update (``|=``) operators. Patch by Brandt Bucher.
..
.. bpo: 32856
.. date: 2018-02-16-10-44-24
.. nonce: UjR8SD
.. section: Core and Builtins
Optimized the idiom for assignment a temporary variable in comprehensions.
Now ``for y in [expr]`` in comprehensions is as fast as a simple assignment
``y = expr``.
..
.. bpo: 30566
.. date: 2020-02-24-03-45-28
.. nonce: qROxty
.. section: Library
Fix :exc:`IndexError` when trying to decode an invalid string with punycode
codec.
..
.. bpo: 39649
.. date: 2020-02-23-21-27-10
.. nonce: qiubSp
.. section: Library
Remove obsolete check for ``__args__`` in ``bdb.Bdb.format_stack_entry``.
..
.. bpo: 39648
.. date: 2020-02-22-12-49-04
.. nonce: Y-9N7F
.. section: Library
Expanded :func:`math.gcd` and :func:`math.lcm` to handle multiple arguments.
..
.. bpo: 39681
.. date: 2020-02-21-13-58-40
.. nonce: zN8hf0
.. section: Library
Fix a regression where the C pickle module wouldn't allow unpickling from a
file-like object that doesn't expose a readinto() method.
..
.. bpo: 35950
.. date: 2020-02-21-02-42-41
.. nonce: 9G3-wl
.. section: Library
Raise :exc:`io.UnsupportedOperation` in :meth:`io.BufferedReader.truncate`
when it is called on a read-only :class:`io.BufferedReader` instance.
..
.. bpo: 39479
.. date: 2020-02-18-12-37-16
.. nonce: j3UcCq
.. section: Library
Add :func:`math.lcm` function: least common multiple.
..
.. bpo: 39674
.. date: 2020-02-18-12-31-24
.. nonce: S_zqVM
.. section: Library
Revert "Do not expose abstract collection classes in the collections module"
change (bpo-25988). Aliases to ABC like collections.Mapping are kept in
Python 3.9 to ease transition from Python 2.7, but will be removed in Python
3.10.
..
.. bpo: 39104
.. date: 2020-02-16-18-49-16
.. nonce: cI5MJY
.. section: Library
Fix hanging ProcessPoolExcutor on ``shutdown(wait=False)`` when a task has
failed pickling.
..
.. bpo: 39627
.. date: 2020-02-13-18-14-15
.. nonce: Q0scyQ
.. section: Library
Fixed TypedDict totality check for inherited keys.
..
.. bpo: 39474
.. date: 2020-02-12-12-01-26
.. nonce: RZMEUH
.. section: Library
Fixed starting position of AST for expressions like ``(a)(b)``, ``(a)[b]``
and ``(a).b``.
..
.. bpo: 21016
.. date: 2020-02-12-10-04-39
.. nonce: bFXPH7
.. section: Library
The :mod:`pydoc` and :mod:`trace` modules now use the :mod:`sysconfig`
module to get the path to the Python standard library, to support uncommon
installation path like ``/usr/lib64/python3.9/`` on Fedora. Patch by Jan
Matějek.
..
.. bpo: 39590
.. date: 2020-02-09-05-51-05
.. nonce: rf98GU
.. section: Library
Collections.deque now holds strong references during deque.__contains__ and
deque.count, fixing crashes.
..
.. bpo: 39586
.. date: 2020-02-08-13-37-00
.. nonce: nfTPxX
.. section: Library
The distutils ``bdist_msi`` command is deprecated in Python 3.9, use
``bdist_wheel`` (wheel packages) instead.
..
.. bpo: 39595
.. date: 2020-02-07-23-14-14
.. nonce: DHwddE
.. section: Library
Improved performance of zipfile.Path for files with a large number of
entries. Also improved performance and fixed minor issue as published with
`importlib_metadata 1.5
<https://importlib-metadata.readthedocs.io/en/latest/history.html#v1-5-0>`_.
..
.. bpo: 39350
.. date: 2020-02-06-13-34-52
.. nonce: wRwup1
.. section: Library
Fix regression in :class:`fractions.Fraction` if the numerator and/or the
denominator is an :class:`int` subclass. The :func:`math.gcd` function is
now used to normalize the *numerator* and *denominator*. :func:`math.gcd`
always return a :class:`int` type. Previously, the GCD type depended on
*numerator* and *denominator*.
..
.. bpo: 39567
.. date: 2020-02-06-10-23-32
.. nonce: VpFBxt
.. section: Library
Added audit for :func:`os.walk`, :func:`os.fwalk`, :meth:`pathlib.Path.glob`
and :meth:`pathlib.Path.rglob`.
..
.. bpo: 39559
.. date: 2020-02-05-18-29-14
.. nonce: L8i5YB
.. section: Library
Remove unused, undocumented argument ``getters`` from :func:`uuid.getnode`
..
.. bpo: 38149
.. date: 2020-02-05-11-24-16
.. nonce: GWsjHE
.. section: Library
:func:`sys.audit` is now called only once per call of :func:`glob.glob` and
:func:`glob.iglob`.
..
.. bpo: 39546
.. date: 2020-02-03-15-12-51
.. nonce: _Kj0Pn
.. section: Library
Fix a regression in :class:`~argparse.ArgumentParser` where
``allow_abbrev=False`` was ignored for long options that used a prefix
character other than "-".
..
.. bpo: 39450
.. date: 2020-02-02-14-46-34
.. nonce: 48R274
.. section: Library
Striped whitespace from docstring before returning it from
:func:`unittest.case.shortDescription`.
..
.. bpo: 12915
.. date: 2020-02-02-10-08-25
.. nonce: d6r50-
.. section: Library
A new function ``resolve_name`` has been added to the ``pkgutil`` module.
This resolves a string of the form ``'a.b.c.d'`` or ``'a.b:c.d'`` to an
object. In the example, ``a.b`` is a package/module and ``c.d`` is an object
within that package/module reached via recursive attribute access.
..
.. bpo: 39353
.. date: 2020-01-30-09-07-16
.. nonce: wTl9hc
.. section: Library
The :func:`binascii.crc_hqx` function is no longer deprecated.
..
.. bpo: 39493
.. date: 2020-01-30-01-13-19
.. nonce: CbFRi7
.. section: Library
Mark ``typing.IO.closed`` as a property
..
.. bpo: 39491
.. date: 2020-01-29-22-47-12
.. nonce: tdl17b
.. section: Library
Add :data:`typing.Annotated` and ``include_extras`` parameter to
:func:`typing.get_type_hints` as part of :pep:`593`. Patch by Till
Varoquaux, documentation by Till Varoquaux and Konstantin Kashin.
..
.. bpo: 39485
.. date: 2020-01-29-14-58-27
.. nonce: Zy3ot6
.. section: Library
Fix a bug in :func:`unittest.mock.create_autospec` that would complain about
the wrong number of arguments for custom descriptors defined in an extension
module returning functions.
..
.. bpo: 38932
.. date: 2020-01-25-13-41-27
.. nonce: 1pu_8I
.. section: Library
Mock fully resets child objects on reset_mock(). Patch by Vegard Stikbakke
..
.. bpo: 39082
.. date: 2020-01-24-13-24-35
.. nonce: qKgrq_
.. section: Library
Allow AsyncMock to correctly patch static/class methods
..
.. bpo: 39432
.. date: 2020-01-23-16-08-58
.. nonce: Cee6mi
.. section: Library
Implement PEP-489 algorithm for non-ascii "PyInit\_..." symbol names in
distutils to make it export the correct init symbol also on Windows.
..
.. bpo: 18819
.. date: 2020-01-20-10-06-19
.. nonce: H4qsoS
.. section: Library
Omit ``devmajor`` and ``devminor`` fields for non-device files in
:mod:`tarfile` archives, enabling bit-for-bit compatibility with GNU
``tar(1)``.
..
.. bpo: 39349
.. date: 2020-01-19-04-12-34
.. nonce: 7CV-LC
.. section: Library
Added a new *cancel_futures* parameter to
:meth:`concurrent.futures.Executor.shutdown` that cancels all pending
futures which have not started running, instead of waiting for them to
complete before shutting down the executor.
..
.. bpo: 39274
.. date: 2020-01-15-23-13-03
.. nonce: lpc0-n
.. section: Library
``bool(fraction.Fraction)`` now returns a boolean even if (numerator != 0)
does not return a boolean (ex: numpy number).
..
.. bpo: 34793
.. date: 2019-12-09-17-24-29
.. nonce: D82Dyu
.. section: Library
Remove support for ``with (await asyncio.lock):`` and ``with (yield from
asyncio.lock):``.  The same is correct for ``asyncio.Condition`` and
``asyncio.Semaphore``.
..
.. bpo: 25597
.. date: 2019-09-12-12-11-05
.. nonce: mPMzVx
.. section: Library
Ensure, if ``wraps`` is supplied to :class:`unittest.mock.MagicMock`, it is
used to calculate return values for the magic methods instead of using the
default return values. Patch by Karthikeyan Singaravelan.
..
.. bpo: 36350
.. date: 2019-03-18-16-17-59
.. nonce: udRSWE
.. section: Library
``inspect.Signature.parameters`` and ``inspect.BoundArguments.arguments`` are
now dicts instead of OrderedDicts. Patch contributed by Rémi Lapeyre.
..
.. bpo: 35727
.. date: 2019-01-12-20-39-34
.. nonce: FWrbHn
.. section: Library
Fix sys.exit() and sys.exit(None) exit code propagation when used in
multiprocessing.Process.
..
.. bpo: 32173
.. date: 2017-12-04-10-14-23
.. nonce: e0C5dF
.. section: Library
* Add ``lazycache`` function to ``__all__``.
* Use ``dict.clear`` to clear the cache.
* Refactoring ``getline`` function and ``checkcache`` function.
..
.. bpo: 17422
.. date: 2020-02-19-11-13-47
.. nonce: g7_9zz
.. section: Documentation
The language reference now specifies restrictions on class namespaces.
Adapted from a patch by Ethan Furman.
..
.. bpo: 39572
.. date: 2020-02-18-18-37-07
.. nonce: CCtzy1
.. section: Documentation
Updated documentation of ``total`` flag of ``TypedDict``.
..
.. bpo: 39654
.. date: 2020-02-18-07-42-20
.. nonce: MoT1jI
.. section: Documentation
In pyclbr doc, update 'class' to 'module' where appropriate and add
readmodule comment. Patch by Hakan Çelik.
..
.. bpo: 39153
.. date: 2020-01-27-22-24-51
.. nonce: Pjl8jV
.. section: Documentation
Clarify refcounting semantics for the following functions: -
PyObject_SetItem - PyMapping_SetItemString - PyDict_SetItem -
PyDict_SetItemString
..
.. bpo: 39392
.. date: 2020-01-27-18-18-42
.. nonce: oiqcLO
.. section: Documentation
Explain that when filling with turtle, overlap regions may be left unfilled.
..
.. bpo: 39369
.. date: 2020-01-17-13-59-21
.. nonce: Bx5yE3
.. section: Documentation
Update mmap readline method description. The fact that the readline method
does update the file position should not be ignored since this might give
the impression for the programmer that it doesn't update it.
..
.. bpo: 9056
.. date: 2018-09-28-18-13-08
.. nonce: -sFOwU
.. section: Documentation
Include subsection in TOC for PDF version of docs.
..
.. bpo: 38325
.. date: 2020-02-11-00-38-32
.. nonce: HgmfoE
.. section: Tests
Skip tests on non-BMP characters of test_winconsoleio.
..
.. bpo: 39502
.. date: 2020-01-30-15-04-54
.. nonce: chbpII
.. section: Tests
Skip test_zipfile.test_add_file_after_2107() if :func:`time.localtime` fails
with :exc:`OverflowError`. It is the case on AIX 6.1 for example.
..
.. bpo: 39489
.. date: 2020-01-29-19-17-02
.. nonce: HKPzv-
.. section: Build
Remove ``COUNT_ALLOCS`` special build.
..
.. bpo: 39553
.. date: 2020-02-04-19-50-53
.. nonce: _EnweA
.. section: Windows
Delete unused code related to SxS manifests.
..
.. bpo: 39439
.. date: 2020-01-24-03-15-05
.. nonce: sFxGfR
.. section: Windows
Honor the Python path when a virtualenv is active on Windows.
..
.. bpo: 39393
.. date: 2020-01-20-23-42-53
.. nonce: gWlJDG
.. section: Windows
Improve the error message when attempting to load a DLL with unresolved
dependencies.
..
.. bpo: 38883
.. date: 2020-01-11-22-53-55
.. nonce: X7FRaN
.. section: Windows
:meth:`~pathlib.Path.home` and :meth:`~pathlib.Path.expanduser` on
Windows now prefer :envvar:`USERPROFILE` and no longer use :envvar:`HOME`,
which is not normally set for regular user accounts. This makes them again
behave like :func:`os.path.expanduser`, which was changed to ignore
:envvar:`HOME` in 3.8, see :issue:`36264`.
..
.. bpo: 39185
.. date: 2020-01-02-01-11-53
.. nonce: T4herN
.. section: Windows
The build.bat script has additional options for very-quiet output (-q) and
very-verbose output (-vv)
..
.. bpo: 39663
.. date: 2020-02-17-21-09-03
.. nonce: wexcsH
.. section: IDLE
Add tests for pyparse find_good_parse_start().
..
.. bpo: 39600
.. date: 2020-02-10-17-09-48
.. nonce: X6NsyM
.. section: IDLE
In the font configuration window, remove duplicated font names.
..
.. bpo: 30780
.. date: 2020-01-27-16-44-29
.. nonce: nR80qu
.. section: IDLE
Add remaining configdialog tests for buttons and highlights and keys tabs.
..
.. bpo: 39388
.. date: 2020-01-25-02-26-45
.. nonce: x4TQNh
.. section: IDLE
IDLE Settings Cancel button now cancels pending changes
..
.. bpo: 38792
.. date: 2019-11-13-23-51-39
.. nonce: xhTC5a
.. section: IDLE
Close an IDLE shell calltip if a :exc:`KeyboardInterrupt` or shell restart
occurs.  Patch by Zackery Spytz.
..
.. bpo: 35081
.. date: 2020-02-12-21-38-49
.. nonce: 5tj1yC
.. section: C API
Move the ``bytes_methods.h`` header file to the internal C API as
``pycore_bytes_methods.h``: it only contains private symbols (prefixed by
``_Py``), except of the ``PyDoc_STRVAR_shared()`` macro.
..
.. bpo: 35081
.. date: 2020-02-12-21-24-02
.. nonce: at7BjN
.. section: C API
Move the ``dtoa.h`` header file to the internal C API as ``pycore_dtoa.h``:
it only contains private functions (prefixed by ``_Py``). The :mod:`math`
and :mod:`cmath` modules must now be compiled with the ``Py_BUILD_CORE``
macro defined.
..
.. bpo: 39573
.. date: 2020-02-07-10-41-53
.. nonce: EG9VDI
.. section: C API
Add :c:func:`Py_SET_SIZE` function to set the size of an object.
..
.. bpo: 39500
.. date: 2020-02-07-09-35-43
.. nonce: xRAEgX
.. section: C API
:c:func:`PyUnicode_IsIdentifier` does not call :c:func:`Py_FatalError`
anymore if the string is not ready.
..
.. bpo: 39573
.. date: 2020-02-07-03-39-03
.. nonce: Oa8cL1
.. section: C API
Add :c:func:`Py_SET_TYPE` function to set the type of an object.
..
.. bpo: 39573
.. date: 2020-02-07-00-23-44
.. nonce: nRD1q7
.. section: C API
Add a :c:func:`Py_SET_REFCNT` function to set the reference counter of an
object.
..
.. bpo: 39542
.. date: 2020-02-05-13-14-20
.. nonce: 5mleGX
.. section: C API
Convert :c:func:`PyType_HasFeature`, :c:func:`PyType_Check` and
:c:func:`PyType_CheckExact` macros to static inline functions.
..
.. bpo: 39542
.. date: 2020-02-05-12-40-51
.. nonce: si-_Zq
.. section: C API
In the limited C API, ``PyObject_INIT()`` and ``PyObject_INIT_VAR()`` are
now defined as aliases to :c:func:`PyObject_Init` and
:c:func:`PyObject_InitVar` to make their implementation opaque. It avoids to
leak implementation details in the limited C API. Exclude the following
functions from the limited C API: ``_Py_NewReference()``,
``_Py_ForgetReference()``, ``_PyTraceMalloc_NewReference()`` and
``_Py_GetRefTotal()``.
..
.. bpo: 39542
.. date: 2020-02-05-12-00-18
.. nonce: RJCUKR
.. section: C API
Exclude trashcan mechanism from the limited C API: it requires access to
PyTypeObject and PyThreadState structure fields, whereas these structures
are opaque in the limited C API.
..
.. bpo: 39511
.. date: 2020-01-31-16-35-21
.. nonce: nv9yEn
.. section: C API
The :c:func:`PyThreadState_Clear` function now calls the
:c:member:`PyThreadState.on_delete` callback. Previously, that happened in
:c:func:`PyThreadState_Delete`.
..
.. bpo: 38076
.. date: 2020-01-17-11-37-05
.. nonce: cxfw2x
.. section: C API
Fix to clear the interpreter state only after clearing module globals to
guarantee module state access from C Extensions during runtime destruction
..
.. bpo: 39245
.. date: 2020-01-07-13-46-40
.. nonce: G7wog6
.. section: C API
The Vectorcall API (PEP 590) was made public, adding the functions
``PyObject_Vectorcall``, ``PyObject_VectorcallMethod``,
``PyVectorcall_Function``, ``PyObject_CallOneArg``,
``PyObject_CallMethodNoArgs``, ``PyObject_CallMethodOneArg``,
``PyObject_FastCallDict``, and the flag ``Py_TPFLAGS_HAVE_VECTORCALL``.

.. date: 2022-11-04-09-29-36
.. gh-issue: 98433
.. nonce: l76c5G
.. release date: 2022-11-14
.. section: Security
The IDNA codec decoder used on DNS hostnames by :mod:`socket` or
:mod:`asyncio` related name resolution functions no longer involves a
quadratic algorithm. This prevents a potential CPU denial of service if an
out-of-spec excessive length hostname involving bidirectional characters
were decoded. Some protocols such as :mod:`urllib` http :samp:`3{xx}` redirects
potentially allow for an attacker to supply such a name.
Individual labels within an IDNA encoded DNS name will now raise an error
early during IDNA decoding if they are longer than 1024 unicode characters
given that each decoded DNS label must be 63 or fewer characters and the
entire decoded DNS name is limited to 255. Only an application presenting a
hostname or label consisting primarily of :rfc:`3454` section 3.1 "Nothing"
characters to be removed would run into of this new limit. See also
:rfc:`5894` section 6 and :rfc:`3491`.
..
.. date: 2022-10-26-21-04-23
.. gh-issue: 98739
.. nonce: keBWcY
.. section: Security
Update bundled libexpat to 2.5.0
..
.. date: 2022-11-11-14-48-17
.. gh-issue: 81057
.. nonce: ik4iOv
.. section: Core and Builtins
The docs clearly say that :c:data:`PyImport_Inittab`,
:c:func:`PyImport_AppendInittab`, and :c:func:`PyImport_ExtendInittab`
should not be used after :c:func:`Py_Initialize` has been called. We now
enforce this for the two functions.  Additionally, the runtime now uses an
internal copy of :c:data:`PyImport_Inittab`, to guard against modification.
..
.. date: 2022-11-09-12-07-24
.. gh-issue: 99298
.. nonce: NeArAJ
.. section: Core and Builtins
Fix an issue that could potentially cause incorrect error handling for some
bytecode instructions.
..
.. date: 2022-11-08-17-47-10
.. gh-issue: 99254
.. nonce: RSvyFt
.. section: Core and Builtins
The compiler now removes all unused constants from code objects (except the
first one, which may be a docstring).
..
.. date: 2022-11-08-16-35-25
.. gh-issue: 99205
.. nonce: 2YOoFT
.. section: Core and Builtins
Fix an issue that prevented :c:type:`PyThreadState` and
:c:type:`PyInterpreterState` memory from being freed properly.
..
.. date: 2022-11-07-14-16-59
.. gh-issue: 81057
.. nonce: 3uKlLQ
.. section: Core and Builtins
The 18 global C variables holding the state of the allocators have been
moved to ``_PyRuntimeState``.  This is a strictly internal change with no
change in behavior.
..
.. date: 2022-11-07-10-29-41
.. gh-issue: 99181
.. nonce: bfG4bI
.. section: Core and Builtins
Fix failure in :keyword:`except* <except_star>` with unhashable exceptions.
..
.. date: 2022-11-07-08-17-12
.. gh-issue: 99204
.. nonce: Mf4hMD
.. section: Core and Builtins
Fix calculation of :data:`sys._base_executable` when inside a POSIX virtual
environment using copies of the python binary when the base installation
does not provide the executable name used by the venv. Calculation will fall
back to alternative names ("python<MAJOR>", "python<MAJOR>.<MINOR>").
..
.. date: 2022-11-06-22-59-02
.. gh-issue: 96055
.. nonce: TmQuJn
.. section: Core and Builtins
Update :mod:`faulthandler` to emit an error message with the proper
unexpected signal number. Patch by Donghee Na.
..
.. date: 2022-11-06-13-25-01
.. gh-issue: 99153
.. nonce: uE3CVL
.. section: Core and Builtins
Fix location of :exc:`SyntaxError` for a :keyword:`try` block with both
:keyword:`except` and :keyword:`except* <except_star>`.
..
.. date: 2022-11-06-00-47-11
.. gh-issue: 98686
.. nonce: DBDy6U
.. section: Core and Builtins
Merge the adaptive opcode logic into each instruction's unquickened variant,
and merge the logic in ``EXTENDED_ARG_QUICK`` into :opcode:`EXTENDED_ARG`.
With these changes, the quickening that happens at code object creation is
now only responsible for initializing warmup counters and inserting
superinstructions.
..
.. date: 2022-11-06-00-17-58
.. gh-issue: 99103
.. nonce: bFA9BX
.. section: Core and Builtins
Fix the error reporting positions of specialized traceback anchors when the
source line contains Unicode characters.
..
.. date: 2022-11-05-18-36-27
.. gh-issue: 99139
.. nonce: cI9vV1
.. section: Core and Builtins
Improve the error suggestion for :exc:`NameError` exceptions for instances.
Now if a :exc:`NameError` is raised in a method and the instance has an
attribute that's exactly equal to the name in the exception, the suggestion
will include ``self.<NAME>`` instead of the closest match in the method
scope. Patch by Pablo Galindo
..
.. date: 2022-11-03-13-11-17
.. gh-issue: 98401
.. nonce: CBS4nv
.. section: Core and Builtins
Octal escapes with value larger than ``0o377`` (ex: ``"\477"``), deprecated
in Python 3.11, now produce a :exc:`SyntaxWarning`, instead of
:exc:`DeprecationWarning`. In a future Python version they will be
eventually a :exc:`SyntaxError`. Patch by Victor Stinner.
..
.. date: 2022-11-02-17-02-06
.. gh-issue: 98401
.. nonce: y-dbVW
.. section: Core and Builtins
A backslash-character pair that is not a valid escape sequence now generates
a :exc:`SyntaxWarning`, instead of :exc:`DeprecationWarning`.  For example,
``re.compile("\d+\.\d+")`` now emits a :exc:`SyntaxWarning` (``"\d"`` is an
invalid escape sequence), use raw strings for regular expression:
``re.compile(r"\d+\.\d+")``. In a future Python version, :exc:`SyntaxError`
will eventually be raised, instead of :exc:`SyntaxWarning`. Patch by Victor
Stinner.
..
.. date: 2022-11-02-14-42-35
.. gh-issue: 96793
.. nonce: q0Oi74
.. section: Core and Builtins
Handle StopIteration and StopAsyncIteration raised in generator or
coroutines in the bytecode, rather than in wrapping C code.
..
.. date: 2022-10-31-22-55-34
.. gh-issue: 98931
.. nonce: AoWZ-4
.. section: Core and Builtins
Improve the :exc:`SyntaxError` error message when the user types ``import x
from y`` instead of ``from y import x``. Patch by Pablo Galindo
..
.. date: 2022-10-31-21-01-35
.. gh-issue: 98852
.. nonce: MYaRN6
.. section: Core and Builtins
Fix subscription of type aliases containing bare generic types or types like
:class:`~typing.TypeVar`: for example ``tuple[A, T][int]`` and
``tuple[TypeVar, T][int]``, where ``A`` is a generic type, and ``T`` is a
type variable.
..
.. date: 2022-10-31-18-03-10
.. gh-issue: 98925
.. nonce: zpdjVd
.. section: Core and Builtins
Lower the recursion depth for marshal on WASI to support (in-development)
wasmtime 2.0.
..
.. date: 2022-10-28-14-52-55
.. gh-issue: 98783
.. nonce: iG0kMs
.. section: Core and Builtins
Fix multiple crashes in debug mode when ``str`` subclasses are used instead
of ``str`` itself.
..
.. date: 2022-10-28-13-59-51
.. gh-issue: 98811
.. nonce: XQypJa
.. section: Core and Builtins
Use complete source locations to simplify detection of ``__future__``
imports which are not at the beginning of the file. Also corrects the offset
in the exception raised in one case, which was off by one and impeded
highlighting.
..
.. date: 2022-10-28-09-42-51
.. gh-issue: 96793
.. nonce: ucBfWO
.. section: Core and Builtins
Add specialization of :opcode:`FOR_ITER` for generators. Saves multiple
layers of dispatch and checking to get from the :opcode:`FOR_ITER`
instruction in the caller to the :opcode:`RESUME` in the generator.
..
.. date: 2022-10-27-16-42-16
.. gh-issue: 98762
.. nonce: Eb2kzg
.. section: Core and Builtins
Fix source locations of :keyword:`match` sub-patterns.
..
.. date: 2022-10-24-10-30-30
.. gh-issue: 98586
.. nonce: Tha5Iy
.. section: Core and Builtins
Added the methods :c:func:`PyObject_Vectorcall` and
:c:func:`PyObject_VectorcallMethod` to the :ref:`Limited API <stable>` along
with the auxiliary macro constant :c:macro:`PY_VECTORCALL_ARGUMENTS_OFFSET`.
The availability of these functions enables more efficient :PEP:`590` vector
calls from binary extension modules that avoid argument boxing/unboxing
overheads.
..
.. date: 2022-10-21-11-28-53
.. gh-issue: 99257
.. nonce: nmcuf-
.. section: Core and Builtins
Fix an issue where member descriptors (such as those for
:attr:`~object.__slots__`) could behave incorrectly or crash instead of
raising a :exc:`TypeError` when accessed via an instance of an invalid type.
..
.. date: 2022-10-19-23-54-43
.. gh-issue: 93143
.. nonce: 1wCYub
.. section: Core and Builtins
Rather than changing :attr:`~types.CodeType.co_code`, the interpreter will
now display a :exc:`RuntimeWarning` and assign :const:`None` to any fast
locals that are left unbound after jumps or :keyword:`del` statements
executed while tracing.
..
.. date: 2022-10-19-15-59-08
.. gh-issue: 96421
.. nonce: e22y3r
.. section: Core and Builtins
When calling into Python code from C code, through
:c:func:`PyEval_EvalFrameEx` or a related C-API function, a shim frame in
inserted into the call stack. This occurs in the
``_PyEval_EvalFrameDefault()`` function. The extra frame should be invisible
to all Python and most C extensions, but out-of-process profilers and
debuggers need to be aware of it. These shim frames can be detected by
checking ``frame->owner == FRAME_OWNED_BY_CSTACK``.
Extensions implementing their own interpreters using PEP 523 need to be
aware of this shim frame and the changes to the semantics of
:opcode:`RETURN_VALUE`, :opcode:`YIELD_VALUE`, and
:opcode:`RETURN_GENERATOR`, which now clear the frame.
..
.. date: 2022-10-19-01-01-08
.. gh-issue: 98415
.. nonce: ZS2eWh
.. section: Build
Fix detection of MAC addresses for :mod:`uuid` on certain OSs. Patch by
Chaim Sanders
..
.. date: 2022-10-16-13-26-46
.. gh-issue: 98686
.. nonce: D9Gu_Q
.. section: Core and Builtins
Quicken all code objects, and specialize adaptive bytecode instructions more
aggressively.
..
.. date: 2022-10-15-23-15-14
.. gh-issue: 92119
.. nonce: PMSwwG
.. section: Core and Builtins
Print exception class name instead of its string representation when raising
errors from :mod:`ctypes` calls.
..
.. date: 2022-10-15-22-25-20
.. gh-issue: 91058
.. nonce: Uo2kW-
.. section: Core and Builtins
:exc:`ImportError` raised from failed ``from <module> import <name>`` now
include suggestions for the value of ``<name>`` based on the available names
in ``<module>``. Patch by Pablo Galindo
..
.. date: 2022-09-13-14-07-06
.. gh-issue: 96793
.. nonce: 7DLRSm
.. section: Core and Builtins
The :opcode:`FOR_ITER` now leaves the iterator on the stack on termination
of the loop. This is to assist specialization of loops for generators.
..
.. date: 2022-09-09-16-32-58
.. gh-issue: 90716
.. nonce: z4yuYq
.. section: Core and Builtins
Add _pylong.py module.  It includes asymptotically faster algorithms that
can be used for operations on integers with many digits.  It is used by
longobject.c to speed up some operations.
..
.. date: 2022-07-30-14-10-27
.. gh-issue: 95389
.. nonce: nSGEkG
.. section: Core and Builtins
Expose :const:`~socket.ETH_P_ALL` and some of the :ref:`ETHERTYPE_* constants
<socket-ethernet-types>` in :mod:`socket`. Patch by Noam Cohen.
..
.. date: 2022-06-10-16-37-44
.. gh-issue: 93696
.. nonce: 65BI2R
.. section: Library
Allow :mod:`pdb` to locate source for frozen modules in the standard
library.
..
.. date: 2022-11-12-15-45-51
.. gh-issue: 99418
.. nonce: FxfAXS
.. section: Library
Fix bug in :func:`urllib.parse.urlparse` that causes URL schemes that begin
with a digit, a plus sign, or a minus sign to be parsed incorrectly.
..
.. date: 2022-11-11-18-23-41
.. gh-issue: 94597
.. nonce: m6vMDK
.. section: Library
Deprecate :class:`asyncio.AbstractChildWatcher` to be removed in Python
3.14. Patch by Kumar Aditya.
..
.. date: 2022-11-10-11-51-39
.. gh-issue: 99305
.. nonce: 6LzQc3
.. section: Library
Improve performance of :func:`secrets.token_hex`.
..
.. date: 2022-11-09-20-48-42
.. gh-issue: 74044
.. nonce: zBj26K
.. section: Library
Fixed bug where :func:`inspect.signature` reported incorrect arguments for
decorated methods.
..
.. date: 2022-11-09-12-16-35
.. gh-issue: 99275
.. nonce: klOqoL
.. section: Library
Fix ``SystemError`` in :mod:`ctypes` when exception was not set during
``__initsubclass__``.
..
.. date: 2022-11-09-08-40-52
.. gh-issue: 99277
.. nonce: J1P44O
.. section: Library
Remove older version of ``_SSLProtocolTransport.get_write_buffer_limits`` in
:mod:`!asyncio.sslproto`
..
.. date: 2022-11-08-11-15-37
.. gh-issue: 99248
.. nonce: 1vt8xI
.. section: Library
fix negative numbers failing in verify()
..
.. date: 2022-11-06-12-44-51
.. gh-issue: 99155
.. nonce: vLZOzi
.. section: Library
Fix :class:`statistics.NormalDist` pickle with ``0`` and ``1`` protocols.
..
.. date: 2022-11-05-23-16-15
.. gh-issue: 93464
.. nonce: ucd4vP
.. section: Library
``enum.auto()`` is now correctly activated when combined with other
assignment values.  E.g. ``ONE = auto(), 'some text'`` will now evaluate as
``(1, 'some text')``.
..
.. date: 2022-11-05-17-16-40
.. gh-issue: 99134
.. nonce: Msgspf
.. section: Library
Update the bundled copy of pip to version 22.3.1.
..
.. date: 2022-11-03-15-28-07
.. gh-issue: 92584
.. nonce: m5ctkm
.. section: Library
Remove the ``distutils`` package. It was deprecated in Python 3.10 by
:pep:`632` "Deprecate distutils module". For projects still using
``distutils`` and cannot be updated to something else, the ``setuptools``
project can be installed: it still provides ``distutils``. Patch by Victor
Stinner.
..
.. date: 2022-11-02-18-27-13
.. gh-issue: 98999
.. nonce: Ai2KDh
.. section: Library
Now :mod:`!_pyio` is consistent with :mod:`!_io` in raising ``ValueError``
when executing methods over closed buffers.
..
.. date: 2022-11-02-05-54-02
.. gh-issue: 83004
.. nonce: 0v8iyw
.. section: Library
Clean up refleak on failed module initialisation in :mod:`!_zoneinfo`
..
.. date: 2022-11-02-05-53-25
.. gh-issue: 83004
.. nonce: qc_KHr
.. section: Library
Clean up refleaks on failed module initialisation in :mod:`!_pickle`
..
.. date: 2022-11-02-05-52-36
.. gh-issue: 83004
.. nonce: LBl79O
.. section: Library
Clean up refleak on failed module initialisation in :mod:`!_io`.
..
.. date: 2022-10-31-12-34-03
.. gh-issue: 98897
.. nonce: rgNn4x
.. section: Library
Fix memory leak in :func:`math.dist` when both points don't have the same
dimension. Patch by Kumar Aditya.
..
.. date: 2022-10-30-22-42-48
.. gh-issue: 98878
.. nonce: fgrykp
.. section: Library
Use the frame bound builtins when offering a name suggestion in
:mod:`traceback` to prevent crashing when ``__builtins__`` is not a dict.
..
.. date: 2022-10-30-15-26-33
.. gh-issue: 98139
.. nonce: qtm-9T
.. section: Library
In :mod:`importlib._bootstrap`, enhance namespace package repr to ``<module
'x' (namespace) from ['path']>``.
..
.. date: 2022-10-29-09-42-20
.. gh-issue: 90352
.. nonce: t8QEPt
.. section: Library
Fix ``_SelectorDatagramTransport`` to inherit from
:class:`~asyncio.DatagramTransport` in :mod:`asyncio`. Patch by Kumar
Aditya.
..
.. date: 2022-10-29-03-40-18
.. gh-issue: 98793
.. nonce: WSPB4A
.. section: Library
Fix argument typechecks in :func:`!_overlapped.WSAConnect` and
:func:`!_overlapped.Overlapped.WSASendTo` functions.
..
.. date: 2022-10-28-23-44-17
.. gh-issue: 98744
.. nonce: sGHDWm
.. section: Library
Prevent crashing in :mod:`traceback` when retrieving the byte-offset for
some source files that contain certain unicode characters.
..
.. date: 2022-10-27-12-56-38
.. gh-issue: 98740
.. nonce: ZoqqGM
.. section: Library
Fix internal error in the :mod:`re` module which in very rare circumstances
prevented compilation of a regular expression containing a :ref:`conditional
expression <re-conditional-expression>` without the "else" branch.
..
.. date: 2022-10-26-07-51-55
.. gh-issue: 98703
.. nonce: 0hW773
.. section: Library
Fix :meth:`asyncio.StreamWriter.drain` to call ``protocol.connection_lost``
callback only once on Windows.
..
.. date: 2022-10-25-20-17-34
.. gh-issue: 98624
.. nonce: YQUPFy
.. section: Library
Add a mutex to unittest.mock.NonCallableMock to protect concurrent access to
mock attributes.
..
.. date: 2022-10-25-07-00-31
.. gh-issue: 98658
.. nonce: nGABW9
.. section: Library
The :class:`array.array` class now supports subscripting, making it a
:term:`generic type`.
..
.. date: 2022-10-15-10-43-45
.. gh-issue: 98284
.. nonce: SaVHTd
.. section: Library
Improved :class:`TypeError` message for undefined abstract methods of a
:class:`abc.ABC` instance. The names of the missing methods are surrounded
by single-quotes to highlight them.
..
.. date: 2022-10-10-07-07-31
.. gh-issue: 96151
.. nonce: K9fwoq
.. section: Library
Allow ``BUILTINS`` to be a valid field name for frozen dataclasses.
..
.. date: 2022-10-08-19-39-27
.. gh-issue: 98086
.. nonce: y---WC
.. section: Library
Make sure ``patch.dict()`` can be applied on async functions.
..
.. date: 2022-09-05-17-08-56
.. gh-issue: 72719
.. nonce: jUpzF3
.. section: Library
Remove modules :mod:`!asyncore` and :mod:`!asynchat`, which were deprecated by
:pep:`594`.
..
.. date: 2022-08-23-03-13-18
.. gh-issue: 96192
.. nonce: TJywOF
.. section: Library
Fix handling of ``bytes`` :term:`path-like objects <path-like object>` in
:func:`os.ismount`.
..
.. date: 2022-06-23-15-36-49
.. gh-issue: 94172
.. nonce: DzQk0s
.. section: Library
:mod:`ftplib`: Remove the ``FTP_TLS.ssl_version`` class attribute: use the
*context* parameter instead. Patch by Victor Stinner
..
.. date: 2022-06-23-15-31-49
.. gh-issue: 94172
.. nonce: AXE2IZ
.. section: Library
Remove the *keyfile* and *certfile* parameters from the
:mod:`ftplib`, :mod:`imaplib`, :mod:`poplib` and :mod:`smtplib` modules,
and the *key_file*, *cert_file* and *check_hostname* parameters from the
:mod:`http.client` module,
all deprecated since Python 3.6. Use the *context*
parameter (*ssl_context* in :mod:`imaplib`) instead. Patch by Victor
Stinner.
..
.. date: 2022-06-14-22-46-05
.. gh-issue: 83638
.. nonce: 73xfGK
.. section: Library
Add the :attr:`~sqlite3.Connection.autocommit` attribute to
:class:`sqlite3.Connection` and the *autocommit* parameter to
:func:`sqlite3.connect` to control :pep:`249`-compliant :ref:`transaction
handling <sqlite3-transaction-control-autocommit>`. Patch by Erlend E.
Aasland.
..
.. date: 2022-05-08-08-47-32
.. gh-issue: 92452
.. nonce: 3pNHe6
.. section: Library
Fixed a race condition that could cause :func:`sysconfig.get_config_var` to
incorrectly return :const:`None` in multi-threaded programs.
..
.. date: 2022-05-03-11-32-29
.. gh-issue: 91803
.. nonce: pI4Juv
.. section: Library
Fix an error when using a method of objects mocked with
:func:`unittest.mock.create_autospec` after it was sealed with
:func:`unittest.mock.seal` function.
..
.. bpo: 38523
.. date: 2020-10-23-22-20-52
.. nonce: CrkxLh
.. section: Library
:func:`shutil.copytree` now applies the *ignore_dangling_symlinks* argument
recursively.
..
.. bpo: 40358
.. date: 2020-04-30-02-15-08
.. nonce: A4ygqe
.. section: Library
Add walk_up argument in :meth:`pathlib.PurePath.relative_to`.
..
.. bpo: 36267
.. date: 2019-09-03-15-45-19
.. nonce: z42Ex7
.. section: Library
Fix IndexError in :class:`argparse.ArgumentParser` when a ``store_true``
action is given an explicit argument.
..
.. date: 2022-10-29-02-33-46
.. gh-issue: 98832
.. nonce: DudEIH
.. section: Documentation
Changes wording of docstring for :func:`pathlib.Path.iterdir`.
..
.. date: 2022-10-06-13-00-28
.. gh-issue: 97966
.. nonce: fz7kFg
.. section: Documentation
Update uname docs to clarify the special nature of the platform attribute
and to indicate when it became late-bound.
..
.. date: 2022-10-31-14-47-49
.. gh-issue: 98903
.. nonce: 7KinCV
.. section: Tests
The Python test suite now fails with exit code 4 if no tests ran. It should
help detecting typos in test names and test methods.
..
.. date: 2022-10-26-15-19-20
.. gh-issue: 98713
.. nonce: Lnu32R
.. section: Tests
Fix a bug in the :mod:`typing` tests where a test relying on
CPython-specific implementation details was not decorated with
``@cpython_only`` and was not skipped on other implementations.
..
.. date: 2022-10-15-07-46-48
.. gh-issue: 87390
.. nonce: asR-Zo
.. section: Tests
Add tests for star-unpacking with PEP 646, and some other miscellaneous PEP
646 tests.
..
.. date: 2022-10-12-14-57-06
.. gh-issue: 96853
.. nonce: ANe-bw
.. section: Tests
Added explicit coverage of ``Py_Initialize`` (and hence ``Py_InitializeEx``)
back to the embedding tests (all other embedding tests migrated to
``Py_InitializeFromConfig`` in Python 3.11)
..
.. bpo: 34272
.. date: 2018-07-29-15-59-51
.. nonce: lVX2uR
.. section: Tests
Some C API tests were moved into the new Lib/test/test_capi/ directory.
..
.. date: 2022-11-04-02-58-10
.. gh-issue: 99086
.. nonce: DV_4Br
.. section: Build
Fix ``-Wimplicit-int`` compiler warning in :program:`configure` check for
``PTHREAD_SCOPE_SYSTEM``.
..
.. date: 2022-11-02-19-25-07
.. gh-issue: 99016
.. nonce: R05NkD
.. section: Build
Fix build with ``PYTHON_FOR_REGEN=python3.8``.
..
.. date: 2022-11-02-18-45-35
.. gh-issue: 97731
.. nonce: zKpTlj
.. section: Build
Specify the full path to the source location for ``make docclean`` (needed
for cross-builds).
..
.. date: 2022-11-02-10-56-40
.. gh-issue: 98949
.. nonce: 3SRD8C
.. section: Build
Drop unused build dependency on ``readelf``.
..
.. date: 2022-11-01-21-45-58
.. gh-issue: 98989
.. nonce: tMxbdB
.. section: Build
Use ``python3.11``, if available, for regeneration and freezing.
..
.. date: 2022-10-28-22-24-26
.. gh-issue: 98831
.. nonce: IXRCRX
.. section: Build
Add new tooling, in ``Tools/cases_generator``, to generate the interpreter
switch statement from a list of opcode definitions. This only affects
adding, modifying or removing instruction definitions. The instruction
definitions now live in ``Python/bytecodes.c``, in the form of a `custom DSL
(under development)
<https://github.com/faster-cpython/ideas/blob/main/3.12/interpreter_definition.md>`__.
The tooling reads this file and writes ``Python/generated_cases.c.h``, which
is then included by ``Python/ceval.c`` to provide most of the cases of the
main interpreter switch.
..
.. date: 2022-10-28-18-53-40
.. gh-issue: 98817
.. nonce: oPqrtt
.. section: Build
Remove PCbuild/lib.pyproj: it's not used for anything, is only a minor
convenience for Visual Studio users (who probably mostly don't even know
about it), and it takes a lot of maintenance effort to keep updated.
..
.. date: 2022-10-27-19-47-31
.. gh-issue: 98776
.. nonce: lt_UOG
.. section: Build
Fix ``make regen-test-levenshtein`` for out-of-tree builds.
..
.. date: 2022-10-26-12-37-52
.. gh-issue: 98707
.. nonce: eVXGEx
.. section: Build
Don't use vendored ``libmpdec`` headers if :option:`--with-system-libmpdec`
is passed to :program:`configure`. Don't use vendored ``libexpat`` headers
if :option:`--with-system-expat` is passed to :program:`configure`.
..
.. date: 2022-11-01-11-07-33
.. gh-issue: 98689
.. nonce: 0f6e_N
.. section: Windows
Update Windows builds to zlib v1.2.13.  v1.2.12 has :cve:`2022-37434`, but the
vulnerable ``inflateGetHeader`` API is not used by Python.
..
.. date: 2022-11-01-00-37-13
.. gh-issue: 98790
.. nonce: fpaPAx
.. section: Windows
Assumes that a missing ``DLLs`` directory means that standard extension
modules are in the executable's directory.
..
.. date: 2022-10-27-20-30-16
.. gh-issue: 98745
.. nonce: v06p4r
.. section: Windows
Update :file:`py.exe` launcher to install 3.11 by default and 3.12 on
request.
..
.. date: 2022-10-26-17-43-09
.. gh-issue: 98692
.. nonce: bOopfZ
.. section: Windows
Fix the :ref:`launcher` ignoring unrecognized shebang lines instead of
treating them as local paths
..
.. date: 2022-10-25-10-34-17
.. gh-issue: 94328
.. nonce: 19NhdU
.. section: Windows
Update Windows installer to use SQLite 3.39.4.
..
.. date: 2022-10-25-10-32-23
.. gh-issue: 94328
.. nonce: W3YNC_
.. section: macOS
Update macOS installer to SQLite 3.39.4.
..
.. date: 2022-11-04-16-13-35
.. gh-issue: 98724
.. nonce: p0urWO
.. section: C API
The :c:macro:`Py_CLEAR`, :c:macro:`Py_SETREF` and :c:macro:`Py_XSETREF`
macros now only evaluate their argument once. If the argument has side
effects, these side effects are no longer duplicated. Patch by Victor
Stinner.
..
.. date: 2022-11-03-17-46-41
.. gh-issue: 98978
.. nonce: KJjBvv
.. section: C API
Fix use-after-free in ``Py_SetPythonHome(NULL)``,
``Py_SetProgramName(NULL)`` and ``_Py_SetProgramFullPath(NULL)`` function
calls. Issue reported by Benedikt Reinartz. Patch by Victor Stinner.
..
.. date: 2022-10-25-17-50-43
.. gh-issue: 98410
.. nonce: NSXYfm
.. section: C API
Add ``getbufferproc`` and ``releasebufferproc`` to the stable API.
..
.. date: 2022-10-24-12-09-17
.. gh-issue: 98610
.. nonce: PLX2Np
.. section: C API
Some configurable capabilities of sub-interpreters have changed. They always
allow subprocesses (:mod:`subprocess`) now, whereas before subprocesses
could be optionally disallowed for a sub-interpreter. Instead
:func:`os.exec` can now be disallowed. Disallowing daemon threads is now
supported.  Disallowing all threads is still allowed, but is never done by
default. Note that the optional restrictions are only available through
``_Py_NewInterpreterFromConfig()``, which isn't a public API. They do not
affect the main interpreter, nor :c:func:`Py_NewInterpreter`.
..
.. date: 2022-10-24-11-26-55
.. gh-issue: 98608
.. nonce: _Q2lNV
.. section: C API
A ``_PyInterpreterConfig`` has been added and ``_Py_NewInterpreter()`` has
been renamed to ``_Py_NewInterpreterFromConfig()``.  The
"isolated_subinterpreters" argument is now a granular config that captures
the previous behavior.  Note that this is all "private" API.
..
.. date: 2022-10-16-15-00-25
.. gh-issue: 96853
.. nonce: V0wiXP
.. section: C API
``Py_InitializeEx`` now correctly calls ``PyConfig_Clear`` after
initializing the interpreter (the omission didn't cause a memory leak only
because none of the dynamically allocated config fields are populated by the
wrapper function)
..
.. date: 2022-08-05-15-26-12
.. gh-issue: 91248
.. nonce: ujirJJ
.. section: C API
Add :c:func:`PyFrame_GetVar` and :c:func:`PyFrame_GetVarString` functions to
get a frame variable by its name. Patch by Victor Stinner.


"""