What's New In Python 3.14

Editor:

TBD

This article explains the new features in Python 3.14, compared to 3.13.

For full details, see the changelog.

注釈

Prerelease users should be aware that this document is currently in draft form. It will be updated substantially as Python 3.14 moves towards release, so it's worth checking back even after reading earlier versions.

Summary -- Release highlights

New Features

Other Language Changes

New Modules

  • None yet.

Improved Modules

ast

Added ast.compare() for comparing two ASTs. (Contributed by Batuhan Taskaya and Jeremy Hylton in bpo-15987.)

os

pathlib

symtable

Optimizations

Deprecated

  • Passing a complex number as the real or imag argument in the complex() constructor is now deprecated; it should only be passed as a single positional argument. (Contributed by Serhiy Storchaka in gh-109218.)

Removed

argparse

  • Remove the type, choices, and metavar parameters of argparse.BooleanOptionalAction. They were deprecated since 3.12.

ast

  • Remove the following classes. They were all deprecated since Python 3.8, and have emitted deprecation warnings since Python 3.12:

    • ast.Num

    • ast.Str

    • ast.Bytes

    • ast.NameConstant

    • ast.Ellipsis

    Use ast.Constant instead. As a consequence of these removals, user-defined visit_Num, visit_Str, visit_Bytes, visit_NameConstant and visit_Ellipsis methods on custom ast.NodeVisitor subclasses will no longer be called when the NodeVisitor subclass is visiting an AST. Define a visit_Constant method instead.

    Also, remove the following deprecated properties on ast.Constant, which were present for compatibility with the now-removed AST classes:

    • ast.Constant.n

    • ast.Constant.s

    Use ast.Constant.value instead.

    (Contributed by Alex Waygood in gh-119562.)

collections.abc

  • Remove collections.abc.ByteString. It had previously raised a DeprecationWarning since Python 3.12.

email

importlib

itertools

  • Remove itertools support for copy, deepcopy, and pickle operations. These had previously raised a DeprecationWarning since Python 3.12. (Contributed by Raymond Hettinger in gh-101588.)

pathlib

  • Remove support for passing additional keyword arguments to pathlib.Path. In previous versions, any such arguments are ignored.

  • Remove support for passing additional positional arguments to pathlib.PurePath.relative_to() and is_relative_to(). In previous versions, any such arguments are joined onto other.

pty

sqlite3

typing

  • Remove typing.ByteString. It had previously raised a DeprecationWarning since Python 3.12.

urllib

Others

Porting to Python 3.14

This section lists previously described changes and other bugfixes that may require changes to your code.

Build Changes

C API Changes

New Features

Porting to Python 3.14

  • In the limited C API 3.14 and newer, Py_TYPE() is now implemented as an opaque function call to hide implementation details. (Contributed by Victor Stinner in gh-120600.)

Deprecated

  • Macros Py_IS_NAN, Py_IS_INFINITY and Py_IS_FINITE are soft deprecated, use instead isnan, isinf and isfinite available from math.h since C99. (Contributed by Sergey B Kirpichev in gh-119613.)

Removed