cpython/Misc/NEWS.d/3.15.0a2.rst

.. date: 2025-11-04-19-20-05
.. gh-issue: 140849
.. nonce: YjB2ZZ
.. release date: 2025-11-18
.. section: Windows

Update bundled liblzma to version 5.8.1.

..

.. date: 2025-11-12-12-54-28
.. gh-issue: 141442
.. nonce: 50dS3P
.. section: Tools/Demos

The iOS testbed now correctly handles test arguments that contain spaces.

..

.. date: 2025-10-29-15-20-19
.. gh-issue: 140702
.. nonce: ZXtW8h
.. section: Tools/Demos

The iOS testbed app will now expose the ``GITHUB_ACTIONS`` environment
variable to iOS apps being tested.

..

.. date: 2025-09-21-10-30-08
.. gh-issue: 139198
.. nonce: Fm7NfU
.. section: Tools/Demos

Remove ``Tools/scripts/checkpip.py`` script.

..

.. date: 2025-09-20-20-31-54
.. gh-issue: 139188
.. nonce: zfcxkW
.. section: Tools/Demos

Remove ``Tools/tz/zdump.py`` script.

..

.. date: 2025-10-23-16-39-49
.. gh-issue: 140482
.. nonce: ZMtyeD
.. section: Tests

Preserve and restore the state of ``stty echo`` as part of the test
environment.

..

.. date: 2025-10-15-00-52-12
.. gh-issue: 140082
.. nonce: fpET50
.. section: Tests

Update ``python -m test`` to set ``FORCE_COLOR=1`` when being run with color
enabled so that :mod:`unittest` which is run by it with redirected output
will output in color.

..

.. date: 2025-07-09-21-45-51
.. gh-issue: 136442
.. nonce: jlbklP
.. section: Tests

Use exitcode ``1`` instead of ``5`` if :func:`unittest.TestCase.setUpClass`
raises an exception

..

.. date: 2025-08-15-23-08-44
.. gh-issue: 137836
.. nonce: b55rhh
.. section: Security

Add support of the "plaintext" element, RAWTEXT elements "xmp", "iframe",
"noembed" and "noframes", and optionally RAWTEXT element "noscript" in
:class:`html.parser.HTMLParser`.

..

.. date: 2025-06-28-13-23-53
.. gh-issue: 136063
.. nonce: aGk0Jv
.. section: Security

:mod:`email.message`: ensure linear complexity for legacy HTTP parameters
parsing. Patch by Bénédikt Tran.

..

.. date: 2025-05-30-22-33-27
.. gh-issue: 136065
.. nonce: bu337o
.. section: Security

Fix quadratic complexity in :func:`os.path.expandvars`.

..

.. date: 2025-11-14-16-24-20
.. gh-issue: 141497
.. nonce: L_CxDJ
.. section: Library

:mod:`ipaddress`: ensure that the methods :meth:`IPv4Network.hosts()
<ipaddress.IPv4Network.hosts>` and :meth:`IPv6Network.hosts()
<ipaddress.IPv6Network.hosts>` always return an iterator.

..

.. date: 2025-11-13-14-51-30
.. gh-issue: 140938
.. nonce: kXsHHv
.. section: Library

The :func:`statistics.stdev` and :func:`statistics.pstdev` functions now
raise a :exc:`ValueError` when the input contains an infinity or a NaN.

..

.. date: 2025-11-12-15-42-47
.. gh-issue: 124111
.. nonce: hTw4OE
.. section: Library

Updated Tcl threading configuration in :mod:`_tkinter` to assume that
threads are always available in Tcl 9 and later.

..

.. date: 2025-11-12-01-49-03
.. gh-issue: 137109
.. nonce: D6sq2B
.. section: Library

The :mod:`os.fork` and related forking APIs will no longer warn in the
common case where Linux or macOS platform APIs return the number of threads
in a process and find the answer to be 1 even when a
:func:`os.register_at_fork` ``after_in_parent=`` callback (re)starts a
thread.

..

.. date: 2025-11-10-01-47-18
.. gh-issue: 141314
.. nonce: baaa28
.. section: Library

Fix assertion failure in :meth:`io.TextIOWrapper.tell` when reading files
with standalone carriage return (``\r``) line endings.

..

.. date: 2025-11-09-18-55-13
.. gh-issue: 141311
.. nonce: qZ3swc
.. section: Library

Fix assertion failure in :func:`!io.BytesIO.readinto` and undefined behavior
arising when read position is above capcity in :class:`io.BytesIO`.

..

.. date: 2025-11-08-13-03-10
.. gh-issue: 87710
.. nonce: XJeZlP
.. section: Library

:mod:`mimetypes`: Update mime type for ``.ai`` files to ``application/pdf``.

..

.. date: 2025-11-07-12-25-46
.. gh-issue: 85524
.. nonce: 9SWFIC
.. section: Library

Update ``io.FileIO.readall``, an implementation of
:meth:`io.RawIOBase.readall`, to follow :class:`io.IOBase` guidelines and
raise :exc:`io.UnsupportedOperation` when a file is in "w" mode rather than
:exc:`OSError`

..

.. date: 2025-11-06-15-11-50
.. gh-issue: 141141
.. nonce: tgIfgH
.. section: Library

Fix a thread safety issue with :func:`base64.b85decode`. Contributed by
Benel Tayar.

..

.. date: 2025-11-04-20-08-41
.. gh-issue: 141018
.. nonce: d_oyOI
.. section: Library

:mod:`mimetypes`: Update ``.exe``, ``.dll``, ``.rtf`` and (when
``strict=False``) ``.jpg`` to their correct IANA mime type.

..

.. date: 2025-11-04-15-40-35
.. gh-issue: 137969
.. nonce: 9VZQVt
.. section: Library

Fix :meth:`annotationlib.ForwardRef.evaluate` returning
:class:`~annotationlib.ForwardRef` objects which don't update with new
globals.

..

.. date: 2025-11-04-12-16-13
.. gh-issue: 75593
.. nonce: EFVhKR
.. section: Library

Add support of :term:`path-like objects <path-like object>` and
:term:`bytes-like objects <bytes-like object>` in :func:`wave.open`.

..

.. date: 2025-11-03-16-23-54
.. gh-issue: 140797
.. nonce: DuFEeR
.. section: Library

The undocumented :class:`!re.Scanner` class now forbids regular expressions
containing capturing groups in its lexicon patterns. Patterns using
capturing groups could previously lead to crashes with segmentation fault.
Use non-capturing groups (?:...) instead.

..

.. date: 2025-11-03-05-38-31
.. gh-issue: 125115
.. nonce: jGS8MN
.. section: Library

Refactor the :mod:`pdb` parsing issue so positional arguments can pass
through intuitively.

..

.. date: 2025-11-02-19-23-32
.. gh-issue: 140815
.. nonce: McEG-T
.. section: Library

:mod:`faulthandler` now detects if a frame or a code object is invalid or
freed. Patch by Victor Stinner.

..

.. date: 2025-11-02-11-46-00
.. gh-issue: 100218
.. nonce: 9Ezfdq
.. section: Library

Correctly set :attr:`~OSError.errno` when :func:`socket.if_nametoindex` or
:func:`socket.if_indextoname` raise an :exc:`OSError`. Patch by Bénédikt
Tran.

..

.. date: 2025-11-02-09-37-22
.. gh-issue: 140734
.. nonce: f8gST9
.. section: Library

:mod:`multiprocessing`: fix off-by-one error when checking the length of a
temporary socket file path. Patch by Bénédikt Tran.

..

.. date: 2025-11-01-14-44-09
.. gh-issue: 140873
.. nonce: kfuc9B
.. section: Library

Add support of non-:term:`descriptor` callables in
:func:`functools.singledispatchmethod`.

..

.. date: 2025-11-01-00-36-14
.. gh-issue: 140874
.. nonce: eAWt3K
.. section: Library

Bump the version of pip bundled in ensurepip to version 25.3

..

.. date: 2025-11-01-00-34-53
.. gh-issue: 140826
.. nonce: JEDd7U
.. section: Library

Now :class:`!winreg.HKEYType` objects are compared by their underlying
Windows registry handle value instead of their object identity.

..

.. date: 2025-10-31-16-25-13
.. gh-issue: 140808
.. nonce: XBiQ4j
.. section: Library

The internal class ``mailbox._ProxyFile`` is no longer a parameterized
generic.

..

.. date: 2025-10-31-15-06-26
.. gh-issue: 140691
.. nonce: JzHGtg
.. section: Library

In :mod:`urllib.request`, when opening a FTP URL fails because a data
connection cannot be made, the control connection's socket is now closed to
avoid a :exc:`ResourceWarning`.

..

.. date: 2025-10-31-13-57-55
.. gh-issue: 103847
.. nonce: VM7TnW
.. section: Library

Fix hang when cancelling process created by
:func:`asyncio.create_subprocess_exec` or
:func:`asyncio.create_subprocess_shell`. Patch by Kumar Aditya.

..

.. date: 2025-10-30-15-33-07
.. gh-issue: 137821
.. nonce: 8_Iavt
.. section: Library

Convert ``_json`` module to use Argument Clinic. Patched by Yoonho Hann.

..

.. date: 2025-10-30-12-36-19
.. gh-issue: 140790
.. nonce: _3T6-N
.. section: Library

Initialize all Pdb's instance variables in ``__init__``,  remove some
hasattr/getattr

..

.. date: 2025-10-29-16-53-00
.. gh-issue: 140766
.. nonce: CNagKF
.. section: Library

Add :func:`enum.show_flag_values` and ``enum.bin`` to ``enum.__all__``.

..

.. date: 2025-10-29-16-12-41
.. gh-issue: 120057
.. nonce: qGj5Dl
.. section: Library

Add :func:`os.reload_environ` to ``os.__all__``.

..

.. date: 2025-10-29-09-40-10
.. gh-issue: 140741
.. nonce: L13UCV
.. section: Library

Fix :func:`profiling.sampling.sample` incorrectly handling a
:exc:`FileNotFoundError` or :exc:`PermissionError`.

..

.. date: 2025-10-28-17-43-51
.. gh-issue: 140228
.. nonce: 8kfHhO
.. section: Library

Avoid making unnecessary filesystem calls for frozen modules in
:mod:`linecache` when the global module cache is not present.

..

.. date: 2025-10-28-02-46-56
.. gh-issue: 139946
.. nonce: aN3_uY
.. section: Library

Error and warning keywords in ``argparse.ArgumentParser`` messages are now
colorized when color output is enabled, fixing a visual inconsistency in
which they remained plain text while other output was colorized.

..

.. date: 2025-10-27-18-29-42
.. gh-issue: 140590
.. nonce: LT9HHn
.. section: Library

Fix arguments checking for the :meth:`!functools.partial.__setstate__` that
may lead to internal state corruption and crash. Patch by Sergey Miryanov.

..

.. date: 2025-10-27-16-01-41
.. gh-issue: 125434
.. nonce: qy0uRA
.. section: Library

Display thread name in :mod:`faulthandler` on Windows. Patch by Victor
Stinner.

..

.. date: 2025-10-27-13-49-31
.. gh-issue: 140634
.. nonce: ULng9G
.. section: Library

Fix a reference counting bug in :meth:`!os.sched_param.__reduce__`.

..

.. date: 2025-10-27-00-40-49
.. gh-issue: 140650
.. nonce: DYJPJ9
.. section: Library

Fix an issue where closing :class:`io.BufferedWriter` could crash if the
closed attribute raised an exception on access or could not be converted to
a boolean.

..

.. date: 2025-10-26-16-24-12
.. gh-issue: 140633
.. nonce: ioayC1
.. section: Library

Ignore :exc:`AttributeError` when setting a module's ``__file__`` attribute
when loading an extension module packaged as Apple Framework.

..

.. date: 2025-10-25-22-55-07
.. gh-issue: 140601
.. nonce: In3MlS
.. section: Library

:func:`xml.etree.ElementTree.iterparse` now emits a :exc:`ResourceWarning`
when the iterator is not explicitly closed and was opened with a filename.
This helps developers identify and fix resource leaks. Patch by Osama
Abdelkader.

..

.. date: 2025-10-25-21-26-16
.. gh-issue: 140593
.. nonce: OxlLc9
.. section: Library

:mod:`xml.parsers.expat`: Fix a memory leak that could affect users with
:meth:`~xml.parsers.expat.xmlparser.ElementDeclHandler` set to a custom
element declaration handler. Patch by Sebastian Pipping.

..

.. date: 2025-10-25-21-04-00
.. gh-issue: 140607
.. nonce: oOZGxS
.. section: Library

Inside :meth:`io.RawIOBase.read`, validate that the count of bytes returned
by :meth:`io.RawIOBase.readinto` is valid (inside the provided buffer).

..

.. date: 2025-10-23-19-39-16
.. gh-issue: 138162
.. nonce: Znw5DN
.. section: Library

Fix :class:`logging.LoggerAdapter` with ``merge_extra=True`` and without the
*extra* argument.

..

.. date: 2025-10-23-13-42-15
.. gh-issue: 140481
.. nonce: XKxWpq
.. section: Library

Improve error message when trying to iterate a Tk widget, image or font.

..

.. date: 2025-10-23-12-12-22
.. gh-issue: 138774
.. nonce: mnh2gU
.. section: Library

:func:`ast.unparse` now generates full source code when handling
:class:`ast.Interpolation` nodes that do not have a specified source.

..

.. date: 2025-10-22-20-52-13
.. gh-issue: 140474
.. nonce: xIWlip
.. section: Library

Fix memory leak in :class:`array.array` when creating arrays from an empty
:class:`str` and the ``u`` type code.

..

.. date: 2025-10-22-12-56-57
.. gh-issue: 140448
.. nonce: GsEkXD
.. section: Library

Change the default of ``suggest_on_error`` to ``True`` in
``argparse.ArgumentParser``.

..

.. date: 2025-10-21-15-54-13
.. gh-issue: 137530
.. nonce: ZyIVUH
.. section: Library

:mod:`dataclasses` Fix annotations for generated ``__init__`` methods by
replacing the annotations that were in-line in the generated source code
with ``__annotate__`` functions attached to the methods.

..

.. date: 2025-10-20-12-33-49
.. gh-issue: 140348
.. nonce: SAKnQZ
.. section: Library

Fix regression in Python 3.14.0 where using the ``|`` operator on a
:class:`typing.Union` object combined with an object that is not a type
would raise an error.

..

.. date: 2025-10-18-15-20-25
.. gh-issue: 76007
.. nonce: SNUzRq
.. section: Library

:mod:`decimal`: Deprecate ``__version__`` and replace with
:data:`decimal.SPEC_VERSION`.

..

.. date: 2025-10-18-14-30-21
.. gh-issue: 76007
.. nonce: peEgcr
.. section: Library

Deprecate ``__version__`` from a :mod:`imaplib`. Patch by Hugo van Kemenade.

..

.. date: 2025-10-17-23-58-11
.. gh-issue: 140272
.. nonce: lhY8uS
.. section: Library

Fix memory leak in the :meth:`!clear` method of the :mod:`dbm.gnu` database.

..

.. date: 2025-10-17-20-42-38
.. gh-issue: 129117
.. nonce: X9jr4p
.. section: Library

:mod:`unicodedata`: Add :func:`~unicodedata.isxidstart` and
:func:`~unicodedata.isxidcontinue` functions to check whether a character
can start or continue a `Unicode Standard Annex #31
<https://www.unicode.org/reports/tr31/>`_ identifier.

..

.. date: 2025-10-17-12-33-01
.. gh-issue: 140251
.. nonce: esM-OX
.. section: Library

Colorize the default import statement ``import asyncio`` in asyncio REPL.

..

.. date: 2025-10-16-22-49-16
.. gh-issue: 140212
.. nonce: llBNd0
.. section: Library

Calendar's HTML formatting now accepts year and month as options.
Previously, running ``python -m calendar -t html 2025 10`` would result in
an error message. It now generates an HTML document displaying the calendar
for the specified month. Contributed by Pål Grønås Drange.

..

.. date: 2025-10-16-17-17-20
.. gh-issue: 135801
.. nonce: faH3fa
.. section: Library

Improve filtering by module in :func:`warnings.warn_explicit` if no *module*
argument is passed. It now tests the module regular expression in the
warnings filter not only against the filename with ``.py`` stripped, but
also against module names constructed starting from different parent
directories of the filename (with ``/__init__.py``, ``.py`` and, on Windows,
``.pyw`` stripped).

..

.. date: 2025-10-16-16-10-11
.. gh-issue: 139707
.. nonce: zR6Qtn
.. section: Library

Improve :exc:`ModuleNotFoundError` error message when a :term:`standard
library` module is missing.

..

.. date: 2025-10-15-21-42-13
.. gh-issue: 140041
.. nonce: _Fka2j
.. section: Library

Fix import of :mod:`ctypes` on Android and Cygwin when ABI flags are
present.

..

.. date: 2025-10-15-20-47-04
.. gh-issue: 140120
.. nonce: 3gffZq
.. section: Library

Fixed a memory leak in :mod:`hmac` when it was using the hacl-star backend.
Discovered by ``@ashm-dev`` using AddressSanitizer.

..

.. date: 2025-10-15-17-23-51
.. gh-issue: 140141
.. nonce: j2mUDB
.. section: Library

The :py:class:`importlib.metadata.PackageNotFoundError` traceback raised
when ``importlib.metadata.Distribution.from_name`` cannot discover a
distribution no longer includes a transient :exc:`StopIteration` exception
trace.

Contributed by Bartosz Sławecki in :gh:`140142`.

..

.. date: 2025-10-15-15-10-34
.. gh-issue: 140166
.. nonce: NtxRez
.. section: Library

:mod:`mimetypes`: Per the `IANA assignment
<https://www.iana.org/assignments/media-types/application/texinfo>`_, update
the MIME type for the ``.texi`` and ``.texinfo`` file formats to
``application/texinfo``, instead of ``application/x-texinfo``.

..

.. date: 2025-10-15-02-26-50
.. gh-issue: 140135
.. nonce: 54JYfM
.. section: Library

Speed up :meth:`io.RawIOBase.readall` by using PyBytesWriter API (about 4x
faster)

..

.. date: 2025-10-14-20-27-06
.. gh-issue: 76007
.. nonce: 2NcUbo
.. section: Library

:mod:`zlib`: Deprecate ``__version__`` and schedule for removal in Python
3.20.

..

.. date: 2025-10-13-11-25-41
.. gh-issue: 136702
.. nonce: uvLGK1
.. section: Library

:mod:`encodings`: Deprecate passing a non-ascii *encoding* name to
:func:`encodings.normalize_encoding` and schedule removal of support for
Python 3.17.

..

.. date: 2025-10-11-09-07-06
.. gh-issue: 139940
.. nonce: g54efZ
.. section: Library

Print clearer error message when using ``pdb`` to attach to a non-existing
process.

..

.. date: 2025-10-02-22-29-00
.. gh-issue: 139462
.. nonce: VZXUHe
.. section: Library

When a child process in a :class:`concurrent.futures.ProcessPoolExecutor`
terminates abruptly, the resulting traceback will now tell you the PID and
exit code of the terminated process. Contributed by Jonathan Berg.

..

.. date: 2025-09-30-12-52-54
.. gh-issue: 63161
.. nonce: mECM1A
.. section: Library

Fix :func:`tokenize.detect_encoding`. Support non-UTF-8 shebang and comments
if non-UTF-8 encoding is specified. Detect decoding error for non-UTF-8
encoding. Detect null bytes in source code.

..

.. date: 2025-09-25-20-16-10
.. gh-issue: 101828
.. nonce: yTxJlJ
.. section: Library

Fix ``'shift_jisx0213'``, ``'shift_jis_2004'``, ``'euc_jisx0213'`` and
``'euc_jis_2004'`` codecs truncating null chars as they were treated as part
of multi-character sequences.

..

.. date: 2025-09-23-09-46-46
.. gh-issue: 139246
.. nonce: pzfM-w
.. section: Library

fix: paste zero-width in default repl width is wrong.

..

.. date: 2025-09-18-21-25-41
.. gh-issue: 83714
.. nonce: TQjDWZ
.. section: Library

Implement :func:`os.statx` on Linux kernel versions 4.11 and later with
glibc versions 2.28 and later.  Contributed by Jeffrey Bosboom and Victor
Stinner.

..

.. date: 2025-09-15-21-03-11
.. gh-issue: 138891
.. nonce: oZFdtR
.. section: Library

Fix ``SyntaxError`` when ``inspect.get_annotations(f, eval_str=True)`` is
called on a function annotated with a :pep:`646` ``star_expression``

..

.. date: 2025-09-13-12-19-17
.. gh-issue: 138859
.. nonce: PxjIoN
.. section: Library

Fix generic type parameterization raising a :exc:`TypeError` when omitting a
:class:`ParamSpec` that has a default which is not a list of types.

..

.. date: 2025-09-12-09-34-37
.. gh-issue: 138764
.. nonce: mokHoY
.. section: Library

Prevent :func:`annotationlib.call_annotate_function` from calling
``__annotate__`` functions that don't support ``VALUE_WITH_FAKE_GLOBALS`` in
a fake globals namespace with empty globals.

Make ``FORWARDREF`` and ``STRING`` annotations fall back to using ``VALUE``
annotations in the case that neither their own format, nor
``VALUE_WITH_FAKE_GLOBALS`` are supported.

..

.. date: 2025-09-11-15-03-37
.. gh-issue: 138775
.. nonce: w7rnSx
.. section: Library

Use of ``python -m`` with :mod:`base64` has been fixed to detect input from
a terminal so that it properly notices EOF.

..

.. date: 2025-09-03-20-18-39
.. gh-issue: 98896
.. nonce: tjez89
.. section: Library

Fix a failure in multiprocessing resource_tracker when SharedMemory names
contain colons. Patch by Rani Pinchuk.

..

.. date: 2025-09-03-18-26-07
.. gh-issue: 138425
.. nonce: cVE9Ho
.. section: Library

Fix partial evaluation of :class:`annotationlib.ForwardRef` objects which
rely on names defined as globals.

..

.. date: 2025-08-26-08-17-56
.. gh-issue: 138151
.. nonce: I6CdAk
.. section: Library

In :mod:`annotationlib`, improve evaluation of forward references to
nonlocal variables that are not yet defined when the annotations are
initially evaluated.

..

.. date: 2025-08-15-20-35-30
.. gh-issue: 69528
.. nonce: qc-Eh_
.. section: Library

The :attr:`~io.FileIO.mode` attribute of files opened in the ``'wb+'`` mode
is now ``'wb+'`` instead of ``'rb+'``.

..

.. date: 2025-08-11-04-52-18
.. gh-issue: 137627
.. nonce: Ku5Yi2
.. section: Library

Speed up :meth:`csv.Sniffer.sniff` delimiter detection by up to 1.6x.

..

.. date: 2025-07-14-09-33-17
.. gh-issue: 55531
.. nonce: Gt2e12
.. section: Library

:mod:`encodings`: Improve :func:`~encodings.normalize_encoding` performance
by implementing the function in C using the private
``_Py_normalize_encoding`` which has been modified to make lowercase
conversion optional.

..

.. date: 2025-07-01-04-57-57
.. gh-issue: 136057
.. nonce: 4-t596
.. section: Library

Fixed the bug in :mod:`pdb` and :mod:`bdb` where ``next`` and ``step`` can't
go over the line if a loop exists in the line.

..

.. date: 2025-06-29-22-01-00
.. gh-issue: 133390
.. nonce: I1DW_3
.. section: Library

Support table, index, trigger, view, column, function, and schema completion
for :mod:`sqlite3`'s :ref:`command-line interface <sqlite3-cli>`.

..

.. date: 2025-06-10-18-02-29
.. gh-issue: 135307
.. nonce: fXGrcK
.. section: Library

:mod:`email`: Fix exception in ``set_content()`` when encoding text and
max_line_length is set to ``0`` or ``None`` (unlimited).

..

.. date: 2025-05-10-15-10-54
.. gh-issue: 133789
.. nonce: I-ZlUX
.. section: Library

Fix unpickling of :mod:`pathlib` objects that were pickled in Python 3.13.

..

.. date: 2025-05-07-22-09-28
.. gh-issue: 133601
.. nonce: 9kUL3P
.. section: Library

Remove deprecated :func:`!typing.no_type_check_decorator`.

..

.. date: 2025-04-18-18-08-05
.. gh-issue: 132686
.. nonce: 6kV_Gs
.. section: Library

Add parameters *inherit_class_doc* and *fallback_to_class_doc* for
:func:`inspect.getdoc`.

..

.. date: 2025-03-12-18-57-10
.. gh-issue: 131116
.. nonce: uTpwXZ
.. section: Library

:func:`inspect.getdoc` now correctly returns an inherited docstring on
:class:`~functools.cached_property` objects if none is given in a subclass.

..

.. date: 2025-03-04-17-19-26
.. gh-issue: 130693
.. nonce: Kv01r8
.. section: Library

Add support for ``-nolinestop``, and ``-strictlimits`` options to
:meth:`!tkinter.Text.search`. Also add the :meth:`!tkinter.Text.search_all`
method for ``-all`` and ``-overlap`` options.

..

.. date: 2024-08-08-12-39-36
.. gh-issue: 122255
.. nonce: J_gU8Y
.. section: Library

In the :mod:`linecache` module and in the Python implementation of the
:mod:`warnings` module, a ``DeprecationWarning`` is issued when
``mod.__loader__`` differs from ``mod.__spec__.loader`` (like in the C
implementation of the :mod:`!warnings` module).

..

.. date: 2024-06-26-16-16-43
.. gh-issue: 121011
.. nonce: qW54eh
.. section: Library

:func:`math.log` now supports arbitrary large integer-like arguments in the
same way as arbitrary large integer arguments.

..

.. date: 2024-05-28-17-14-30
.. gh-issue: 119668
.. nonce: RrIGpn
.. section: Library

Publicly expose and document :class:`importlib.machinery.NamespacePath`.

..

.. date: 2023-03-21-10-59-40
.. gh-issue: 102431
.. nonce: eUDnf4
.. section: Library

Clarify constraints for "logical" arguments in methods of
:class:`decimal.Context`.

..

.. date: 2019-06-02-13-56-16
.. gh-issue: 81313
.. nonce: axawSH
.. section: Library

Add the :mod:`math.integer` module (:pep:`791`).

..

.. date: 2025-11-15-01-21-00
.. gh-issue: 141579
.. nonce: aB7cD9
.. section: Core and Builtins

Fix :func:`sys.activate_stack_trampoline` to properly support the
``perf_jit`` backend. Patch by Pablo Galindo.

..

.. date: 2025-11-14-16-25-15
.. gh-issue: 114203
.. nonce: n3tlQO
.. section: Core and Builtins

Skip locking if object is already locked by two-mutex critical section.

..

.. date: 2025-11-14-00-19-45
.. gh-issue: 141528
.. nonce: VWdax1
.. section: Core and Builtins

Suggest using :meth:`concurrent.interpreters.Interpreter.close` instead of
the private ``_interpreters.destroy`` function when warning about remaining
subinterpreters. Patch by Sergey Miryanov.

..

.. date: 2025-11-11-13-40-45
.. gh-issue: 141367
.. nonce: I5KY7F
.. section: Core and Builtins

Specialize ``CALL_LIST_APPEND`` instruction only for lists, not for list
subclasses, to avoid unnecessary deopt. Patch by Mikhail Efimov.

..

.. date: 2025-11-10-23-07-06
.. gh-issue: 141312
.. nonce: H-58GB
.. section: Core and Builtins

Fix the assertion failure in the ``__setstate__`` method of the range
iterator when a non-integer argument is passed. Patch by Sergey Miryanov.

..

.. date: 2025-11-05-19-50-37
.. gh-issue: 140643
.. nonce: QCEOqG
.. section: Core and Builtins

Add support for ``<GC>`` and ``<native>`` frames to
:mod:`!profiling.sampling` output to denote active garbage collection and
calls to native code.

..

.. date: 2025-11-04-12-18-06
.. gh-issue: 140942
.. nonce: GYns6n
.. section: Core and Builtins

Add ``.cjs`` to :mod:`mimetypes` to give CommonJS modules a MIME type of
``application/node``.

..

.. date: 2025-11-04-04-57-24
.. gh-issue: 140479
.. nonce: lwQ2v2
.. section: Core and Builtins

Update JIT compilation to use LLVM 21 at build time.

..

.. date: 2025-11-03-17-21-38
.. gh-issue: 140939
.. nonce: FVboAw
.. section: Core and Builtins

Fix memory leak when :class:`bytearray` or :class:`bytes` is formated with
the ``%*b`` format with a large width that results in a :exc:`MemoryError`.

..

.. date: 2025-11-02-15-28-33
.. gh-issue: 140260
.. nonce: JNzlGz
.. section: Core and Builtins

Fix :mod:`struct` data race in endian table initialization with
subinterpreters. Patch by Shamil Abdulaev.

..

.. date: 2025-11-02-12-47-38
.. gh-issue: 140530
.. nonce: S934bp
.. section: Core and Builtins

Fix a reference leak when ``raise exc from cause`` fails. Patch by Bénédikt
Tran.

..

.. date: 2025-10-31-14-03-42
.. gh-issue: 90344
.. nonce: gvZigO
.. section: Core and Builtins

Replace :class:`io.IncrementalNewlineDecoder` with non incremental newline
decoders in codebase where :meth:`!io.IncrementalNewlineDecoder.decode` was
being called once.

..

.. date: 2025-10-29-20-59-10
.. gh-issue: 140373
.. nonce: -uoaPP
.. section: Core and Builtins

Correctly emit ``PY_UNWIND`` event when generator object is closed. Patch by
Mikhail Efimov.

..

.. date: 2025-10-29-11-31-59
.. gh-issue: 140729
.. nonce: t9JsNt
.. section: Core and Builtins

Fix pickling error in the sampling profiler when using
``concurrent.futures.ProcessPoolExecutor`` script can not be properly
pickled and executed in worker processes.

..

.. date: 2025-10-25-21-31-43
.. gh-issue: 131527
.. nonce: V-JVNP
.. section: Core and Builtins

Dynamic borrow checking for stackrefs is added to ``Py_STACKREF_DEBUG``
mode. Patch by Mikhail Efimov.

..

.. date: 2025-10-25-17-36-46
.. gh-issue: 140576
.. nonce: kj0SCY
.. section: Core and Builtins

Fixed crash in :func:`tokenize.generate_tokens` in case of specific
incorrect input. Patch by Mikhail Efimov.

..

.. date: 2025-10-25-07-25-52
.. gh-issue: 140544
.. nonce: lwjtQe
.. section: Core and Builtins

Speed up accessing interpreter state by caching it in a thread local
variable. Patch by Kumar Aditya.

..

.. date: 2025-10-24-20-42-33
.. gh-issue: 140551
.. nonce: -9swrl
.. section: Core and Builtins

Fixed crash in :class:`dict` if :meth:`dict.clear` is called at the lookup
stage. Patch by Mikhail Efimov and Inada Naoki.

..

.. date: 2025-10-24-20-16-42
.. gh-issue: 140517
.. nonce: cqun-K
.. section: Core and Builtins

Fixed a reference leak when iterating over the result of :func:`map` with
``strict=True`` when the input iterables have different lengths. Patch by
Mikhail Efimov.

..

.. date: 2025-10-24-14-29-12
.. gh-issue: 133467
.. nonce: A5d6TM
.. section: Core and Builtins

Fix race when updating :attr:`!type.__bases__` that could allow a read of
:attr:`!type.__base__` to observe an inconsistent value on the free threaded
build.

..

.. date: 2025-10-23-16-05-50
.. gh-issue: 140471
.. nonce: Ax_aXn
.. section: Core and Builtins

Fix potential buffer overflow in :class:`ast.AST` node initialization when
encountering malformed :attr:`~ast.AST._fields` containing non-:class:`str`.

..

.. date: 2025-10-22-23-26-37
.. gh-issue: 140443
.. nonce: wT5i1A
.. section: Core and Builtins

The logarithm functions (such as :func:`math.log10` and :func:`math.log`)
may now produce slightly different results for extremely large integers that
cannot be converted to floats without overflow. These results are generally
more accurate, with reduced worst-case error and a tighter overall error
distribution.

..

.. date: 2025-10-22-17-22-22
.. gh-issue: 140431
.. nonce: m8D_A-
.. section: Core and Builtins

Fix a crash in Python's :term:`garbage collector <garbage collection>` due
to partially initialized :term:`coroutine` objects when coroutine origin
tracking depth is enabled (:func:`sys.set_coroutine_origin_tracking_depth`).

..

.. date: 2025-10-22-12-48-05
.. gh-issue: 140476
.. nonce: F3-d1P
.. section: Core and Builtins

Optimize :c:func:`PySet_Add` for :class:`frozenset` in :term:`free threaded
<free threading>` build.

..

.. date: 2025-10-22-11-30-16
.. gh-issue: 135904
.. nonce: 3WE5oW
.. section: Core and Builtins

Add special labels to the assembly created during stencil creation to
support relocations that the native object file format does not support.
Specifically, 19 bit branches for AArch64 in Mach-O object files.

..

.. date: 2025-10-21-09-20-03
.. gh-issue: 140398
.. nonce: SoABwJ
.. section: Core and Builtins

Fix memory leaks in :mod:`readline` functions
:func:`~readline.read_init_file`, :func:`~readline.read_history_file`,
:func:`~readline.write_history_file`, and
:func:`~readline.append_history_file` when :c:func:`PySys_Audit` fails.

..

.. date: 2025-10-21-06-51-50
.. gh-issue: 140406
.. nonce: 0gJs8M
.. section: Core and Builtins

Fix memory leak when an object's :meth:`~object.__hash__` method returns an
object that isn't an :class:`int`.

..

.. date: 2025-10-20-11-24-36
.. gh-issue: 140358
.. nonce: UQuKdV
.. section: Core and Builtins

Restore elapsed time and unreachable object count in GC debug output. These
were inadvertently removed during a refactor of ``gc.c``. The debug log now
again reports elapsed collection time and the number of unreachable objects.
Contributed by Pål Grønås Drange.

..

.. date: 2025-10-19-10-32-28
.. gh-issue: 136895
.. nonce: HfsEh0
.. section: Core and Builtins

Update JIT compilation to use LLVM 20 at build time.

..

.. date: 2025-10-18-21-50-44
.. gh-issue: 139109
.. nonce: 9QQOzN
.. section: Core and Builtins

A new tracing frontend for the JIT compiler has been implemented. Patch by
Ken Jin. Design for CPython by Ken Jin, Mark Shannon and Brandt Bucher.

..

.. date: 2025-10-18-21-29-45
.. gh-issue: 140306
.. nonce: xS5CcS
.. section: Core and Builtins

Fix memory leaks in cross-interpreter channel operations and shared
namespace handling.

..

.. date: 2025-10-18-19-52-20
.. gh-issue: 116738
.. nonce: NLJW0L
.. section: Core and Builtins

Make _suggestions module thread-safe on the :term:`free threaded <free
threading>` build.

..

.. date: 2025-10-18-18-08-36
.. gh-issue: 140301
.. nonce: m-2HxC
.. section: Core and Builtins

Fix memory leak of ``PyConfig`` in subinterpreters.

..

.. date: 2025-10-17-20-23-19
.. gh-issue: 140257
.. nonce: 8Txmem
.. section: Core and Builtins

Fix data race between interpreter_clear() and take_gil() on eval_breaker
during finalization with daemon threads.

..

.. date: 2025-10-17-18-03-12
.. gh-issue: 139951
.. nonce: IdwM2O
.. section: Core and Builtins

Fixes a regression in GC performance for a growing heap composed mostly of
small tuples.

*  Counts number of actually tracked objects, instead of trackable objects.
   This ensures that untracking tuples has the desired effect of reducing GC overhead.
*  Does not track most untrackable tuples during creation.
   This prevents large numbers of small tuples causing excessive GCs.

..

.. date: 2025-10-17-14-38-10
.. gh-issue: 140253
.. nonce: gCqFaL
.. section: Core and Builtins

Wrong placement of a double-star pattern inside a mapping pattern now throws
a specialized syntax error. Contributed by Bartosz Sławecki in :gh:`140253`.

..

.. date: 2025-10-16-21-47-00
.. gh-issue: 140104
.. nonce: A8SQIm
.. section: Core and Builtins

Fix a bug with exception handling in the JIT. Patch by Ken Jin. Bug reported
by Daniel Diniz.

..

.. date: 2025-10-15-17-12-32
.. gh-issue: 140149
.. nonce: cy1m3d
.. section: Core and Builtins

Speed up parsing bytes literals concatenation by using PyBytesWriter API and
a single memory allocation (about 3x faster).

..

.. date: 2025-10-15-00-21-40
.. gh-issue: 140061
.. nonce: J0XeDV
.. section: Core and Builtins

Fixing the checking of whether an object is uniquely referenced to ensure
free-threaded compatibility. Patch by Sergey Miryanov.

..

.. date: 2025-10-14-20-18-31
.. gh-issue: 140080
.. nonce: 8ROjxW
.. section: Core and Builtins

Fix hang during finalization when attempting to call :mod:`atexit` handlers
under no memory.

..

.. date: 2025-10-14-18-24-16
.. gh-issue: 139871
.. nonce: SWtuUz
.. section: Core and Builtins

Update :class:`bytearray` to use a :class:`bytes` under the hood as its
buffer and add :func:`bytearray.take_bytes` to take it out.

..

.. date: 2025-10-14-17-07-37
.. gh-issue: 140067
.. nonce: ID2gOm
.. section: Core and Builtins

Fix memory leak in sub-interpreter creation.

..

.. date: 2025-10-13-13-54-19
.. gh-issue: 139914
.. nonce: M-y_3E
.. section: Core and Builtins

Restore support for HP PA-RISC, which has an upwards-growing stack.

..

.. date: 2025-10-12-01-12-12
.. gh-issue: 139817
.. nonce: PAn-8Z
.. section: Core and Builtins

Attribute ``__qualname__`` is added to :class:`typing.TypeAliasType`. Patch
by Mikhail Efimov.

..

.. date: 2025-10-06-14-19-47
.. gh-issue: 135801
.. nonce: OhxEZS
.. section: Core and Builtins

Many functions related to compiling or parsing Python code, such as
:func:`compile`, :func:`ast.parse`, :func:`symtable.symtable`, and
:func:`importlib.abc.InspectLoader.source_to_code` now allow to specify the
module name. It is needed to unambiguous :ref:`filter <warning-filter>`
syntax warnings by module name.

..

.. date: 2025-10-06-10-03-37
.. gh-issue: 139640
.. nonce: gY5oTb2
.. section: Core and Builtins

:func:`ast.parse` no longer emits syntax warnings for
``return``/``break``/``continue`` in ``finally`` (see :pep:`765`) -- they
are only emitted during compilation.

..

.. date: 2025-10-06-10-03-37
.. gh-issue: 139640
.. nonce: gY5oTb
.. section: Core and Builtins

Fix swallowing some syntax warnings in different modules if they
accidentally have the same message and are emitted from the same line. Fix
duplicated warnings in the ``finally`` block.

..

.. date: 2025-10-03-17-51-43
.. gh-issue: 139475
.. nonce: _684ED
.. section: Core and Builtins

Changes in stackref debugging mode when ``Py_STACKREF_DEBUG`` is set. We use
the same pattern of refcounting for stackrefs as in production build.

..

.. date: 2025-09-23-21-01-12
.. gh-issue: 139269
.. nonce: 1rIaxy
.. section: Core and Builtins

Fix undefined behavior when using unaligned store in JIT's ``patch_*``
functions.

..

.. date: 2025-09-15-13-06-11
.. gh-issue: 138944
.. nonce: PeCgLb
.. section: Core and Builtins

Fix :exc:`SyntaxError` message when invalid syntax appears on the same line
as a valid ``import ... as ...`` or ``from ... import ... as ...``
statement. Patch by Brian Schubert.

..

.. date: 2025-09-13-01-23-25
.. gh-issue: 138857
.. nonce: YQ5gdc
.. section: Core and Builtins

Improve :exc:`SyntaxError` message for ``case`` keyword placed outside
:keyword:`match` body.

..

.. date: 2025-07-29-17-51-14
.. gh-issue: 131253
.. nonce: GpRjWy
.. section: Core and Builtins

Support the ``--enable-pystats`` build option for the free-threaded build.

..

.. date: 2025-07-08-00-41-46
.. gh-issue: 136327
.. nonce: 7AiTb_
.. section: Core and Builtins

Errors when calling functions with invalid values after ``*`` and ``**`` now
do not include the function name. Patch by Ilia Solin.

..

.. date: 2025-06-24-13-12-58
.. gh-issue: 134786
.. nonce: MF0VVk
.. section: Core and Builtins

If :c:macro:`Py_TPFLAGS_MANAGED_DICT` and
:c:macro:`Py_TPFLAGS_MANAGED_WEAKREF` are used, then
:c:macro:`Py_TPFLAGS_HAVE_GC` must be used as well.

..

.. date: 2025-11-10-11-26-26
.. gh-issue: 141341
.. nonce: OsO6-y
.. section: C API

On Windows, rename the ``COMPILER`` macro to ``_Py_COMPILER`` to avoid name
conflicts. Patch by Victor Stinner.

..

.. date: 2025-11-08-10-51-50
.. gh-issue: 116146
.. nonce: pCmx6L
.. section: C API

Add a new :c:func:`PyImport_CreateModuleFromInitfunc` C-API for creating a
module from a *spec* and *initfunc*. Patch by Itamar Oren.

..

.. date: 2025-11-06-06-28-14
.. gh-issue: 141042
.. nonce: brOioJ
.. section: C API

Make qNaN in :c:func:`PyFloat_Pack2` and :c:func:`PyFloat_Pack4`, if while
conversion to a narrower precision floating-point format --- the remaining
after truncation payload will be zero.  Patch by Sergey B Kirpichev.

..

.. date: 2025-11-05-05-45-49
.. gh-issue: 141004
.. nonce: N9Ooh9
.. section: C API

:c:macro:`!Py_MATH_El` and :c:macro:`!Py_MATH_PIl` are deprecated.

..

.. date: 2025-11-05-04-38-16
.. gh-issue: 141004
.. nonce: rJL43P
.. section: C API

The :c:macro:`!Py_INFINITY` macro is :term:`soft deprecated`.

..

.. date: 2025-10-26-16-45-28
.. gh-issue: 140556
.. nonce: s__Dae
.. section: C API

:pep:`793`: Add a new entry point for C extension modules,
``PyModExport_<modulename>``.

..

.. date: 2025-10-26-16-45-06
.. gh-issue: 140487
.. nonce: fGOqss
.. section: C API

Fix :c:macro:`Py_RETURN_NOTIMPLEMENTED` in limited C API 3.11 and older:
don't treat ``Py_NotImplemented`` as immortal. Patch by Victor Stinner.

..

.. date: 2025-10-15-15-59-59
.. gh-issue: 140153
.. nonce: BO7sH4
.. section: C API

Fix :c:func:`Py_REFCNT` definition on limited C API 3.11-3.13. Patch by
Victor Stinner.

..

.. date: 2025-10-06-22-17-47
.. gh-issue: 139653
.. nonce: 6-1MOd
.. section: C API

Add :c:func:`PyUnstable_ThreadState_SetStackProtection` and
:c:func:`PyUnstable_ThreadState_ResetStackProtection` functions to set the
stack protection base address and stack protection size of a Python thread
state. Patch by Victor Stinner.

..

.. date: 2025-10-31-13-20-16
.. gh-issue: 140454
.. nonce: gF6dCe
.. section: Build

When building the JIT, match the jit_stencils filename expectations in
Makefile with the generator script. This avoid needless JIT recompilation
during ``make install``.

..

.. date: 2025-10-29-12-30-38
.. gh-issue: 140768
.. nonce: ITYrzw
.. section: Build

Warn when the WASI SDK version doesn't match what's supported.

..

.. date: 2025-10-25-08-07-06
.. gh-issue: 140513
.. nonce: 6OhLTs
.. section: Build

Generate a clear compilation error when ``_Py_TAIL_CALL_INTERP`` is enabled
but either ``preserve_none`` or ``musttail`` is not supported.

..

.. date: 2025-10-22-12-44-07
.. gh-issue: 140475
.. nonce: OhzQbR
.. section: Build

Support WASI SDK 25.

..

.. date: 2025-10-17-11-33-45
.. gh-issue: 140239
.. nonce: _k-GgW
.. section: Build

Check ``statx`` availability only on Linux (including Android).

..

.. date: 2025-10-16-11-30-53
.. gh-issue: 140189
.. nonce: YCrUyt
.. section: Build

iOS builds were added to CI.

..

.. date: 2025-08-10-22-28-06
.. gh-issue: 137618
.. nonce: FdNvIE
.. section: Build

``PYTHON_FOR_REGEN`` now requires Python 3.10 to Python 3.15. Patch by Adam
Turner.