Pending removal in Python 3.14
------------------------------
* :mod:`argparse`: The *type*, *choices*, and *metavar* parameters
of :class:`!argparse.BooleanOptionalAction` are deprecated
and will be removed in 3.14.
(Contributed by Nikita Sobolev in :gh:`92248`.)
* :mod:`ast`: The following features have been deprecated in documentation
since Python 3.8, now cause a :exc:`DeprecationWarning` to be emitted at
runtime when they are accessed or used, and will be removed in Python 3.14:
* :class:`!ast.Num`
* :class:`!ast.Str`
* :class:`!ast.Bytes`
* :class:`!ast.NameConstant`
* :class:`!ast.Ellipsis`
Use :class:`ast.Constant` instead.
(Contributed by Serhiy Storchaka in :gh:`90953`.)
* :mod:`asyncio`:
* The child watcher classes :class:`!asyncio.MultiLoopChildWatcher`,
:class:`!asyncio.FastChildWatcher`, :class:`!asyncio.AbstractChildWatcher`
and :class:`!asyncio.SafeChildWatcher` are deprecated and
will be removed in Python 3.14.
(Contributed by Kumar Aditya in :gh:`94597`.)
* :func:`!asyncio.set_child_watcher`, :func:`!asyncio.get_child_watcher`,
:meth:`!asyncio.AbstractEventLoopPolicy.set_child_watcher` and
:meth:`!asyncio.AbstractEventLoopPolicy.get_child_watcher` are deprecated
and will be removed in Python 3.14.
(Contributed by Kumar Aditya in :gh:`94597`.)
* The :meth:`~asyncio.get_event_loop` method of the
default event loop policy now emits a :exc:`DeprecationWarning` if there
is no current event loop set and it decides to create one.
(Contributed by Serhiy Storchaka and Guido van Rossum in :gh:`100160`.)
* :mod:`collections.abc`: Deprecated :class:`!collections.abc.ByteString`.
Prefer :class:`!Sequence` or :class:`~collections.abc.Buffer`.
For use in typing, prefer a union, like ``bytes | bytearray``,
or :class:`collections.abc.Buffer`.
(Contributed by Shantanu Jain in :gh:`91896`.)
* :mod:`email`: Deprecated the *isdst* parameter in :func:`email.utils.localtime`.
(Contributed by Alan Williams in :gh:`72346`.)
* :mod:`importlib.abc` deprecated classes:
* :class:`!importlib.abc.ResourceReader`
* :class:`!importlib.abc.Traversable`
* :class:`!importlib.abc.TraversableResources`
Use :mod:`importlib.resources.abc` classes instead:
* :class:`importlib.resources.abc.Traversable`
* :class:`importlib.resources.abc.TraversableResources`
(Contributed by Jason R. Coombs and Hugo van Kemenade in :gh:`93963`.)
* :mod:`itertools` had undocumented, inefficient, historically buggy,
and inconsistent support for copy, deepcopy, and pickle operations.
This will be removed in 3.14 for a significant reduction in code
volume and maintenance burden.
(Contributed by Raymond Hettinger in :gh:`101588`.)
* :mod:`multiprocessing`: The default start method will change to a safer one on
Linux, BSDs, and other non-macOS POSIX platforms where ``'fork'`` is currently
the default (:gh:`84559`). Adding a runtime warning about this was deemed too
disruptive as the majority of code is not expected to care. Use the
:func:`~multiprocessing.get_context` or
:func:`~multiprocessing.set_start_method` APIs to explicitly specify when
your code *requires* ``'fork'``. See :ref:`multiprocessing-start-methods`.
* :mod:`pathlib`: :meth:`~pathlib.PurePath.is_relative_to` and
:meth:`~pathlib.PurePath.relative_to`: passing additional arguments is
deprecated.
* :mod:`pkgutil`: :func:`!pkgutil.find_loader` and :func:!pkgutil.get_loader`
now raise :exc:`DeprecationWarning`;
use :func:`importlib.util.find_spec` instead.
(Contributed by Nikita Sobolev in :gh:`97850`.)
* :mod:`pty`:
* ``master_open()``: use :func:`pty.openpty`.
* ``slave_open()``: use :func:`pty.openpty`.
* :mod:`sqlite3`:
* :data:`!version` and :data:`!version_info`.
* :meth:`~sqlite3.Cursor.execute` and :meth:`~sqlite3.Cursor.executemany`
if :ref:`named placeholders <sqlite3-placeholders>` are used and
*parameters* is a sequence instead of a :class:`dict`.
* :mod:`typing`: :class:`!typing.ByteString`, deprecated since Python 3.9,
now causes a :exc:`DeprecationWarning` to be emitted when it is used.
* :mod:`urllib`:
:class:`!urllib.parse.Quoter` is deprecated: it was not intended to be a
public API.
(Contributed by Gregory P. Smith in :gh:`88168`.)