Pending removal in Python 3.14

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: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:urllib: :class:!urllib.parse.Quoter is deprecated: it was not intended to be a public API. (Contributed by Gregory P. Smith in :gh:88168.)