typing_extensions.get_protocol_members and typing_extensions.is_protocol (backport of CPython PR #104878). Patch by Jelle Zijlstra.typing_extensions now re-exports all names in the standard library's typing module, except the deprecated ByteString. Patch by Jelle Zijlstra.typing_extensions.Protocol, typing.runtime_checkable can now be used on typing_extensions.Protocol (previously, users had to use typing_extensions.runtime_checkable if they were using typing_extensions.Protocol).TypedDict with the implementation in the standard library on Python 3.9 and higher. typing_extensions.TypedDict is now a function instead of a class. The private functions _check_fails, _dict_new, and _typeddict_new have been removed. is_typeddict now returns False when called with TypedDict itself as the argument. Patch by Jelle Zijlstra.TypedDict classes through the keyword-argument syntax. Patch by Jelle Zijlstra.issubclass(object, typing_extensions.Protocol) would erroneously raise TypeError. Patch by Alex Waygood (backporting the CPython PR https://github.com/python/cpython/pull/105239).Protocol classes to inherit from typing_extensions.Buffer or collections.abc.Buffer. Patch by Alex Waygood (backporting https://github.com/python/cpython/pull/104827, by Jelle Zijlstra).typing.Protocol and typing_extensions.Protocol simultaneously. Since v4.6.0, this caused TypeError to be raised due to a metaclass conflict. Patch by Alex Waygood.TypedDicts and NamedTuples. CPython PRs #105609 and #105780 by Alex Waygood; typing_extensions backport by Jelle Zijlstra.NamedTuple using the functional syntax with keyword arguments (NT = NamedTuple("NT", a=int)) is now deprecated.NamedTuple with zero fields using the syntax NT = NamedTuple("NT") or NT = NamedTuple("NT", None) is now deprecated.TypedDict with zero fields using the syntax TD = TypedDict("TD") or TD = TypedDict("TD", None) is now deprecated.X that had a member a would not be considered an implicit subclass of an unrelated protocol Y that only has a member a. Where the members of X are a superset of the members of Y, X should always be considered a subclass of Y iff Y is a runtime-checkable protocol that only has callable members. Patch by Alex Waygood (backporting CPython PR https://github.com/python/cpython/pull/105835).class Foo(X, typing_extensions.Protocol), where X was a class that had abc.ABCMeta as its metaclass, would then cause subsequent isinstance(1, X) calls to erroneously raise TypeError. Patch by Alex Waygood (backporting the CPython PR https://github.com/python/cpython/pull/105152).typing_extensions is distributed under the same license as CPython itself.typing_extensions test suite now passes on 3.12.0b1.@deprecated on classes with __new__ but no __init__. Patch by Jelle Zijlstra.isinstance() would cause AttributeError to be raised if using Python 3.7.@runtime to formal API @runtime_checkable in the error message. Patch by Xuehai Pan.Protocol that was generic over a ParamSpec or a TypeVarTuple would cause TypeError to be raised. Patch by Alex Waygood.typing_extensions is now documented at https://typing-extensions.readthedocs.io/en/latest/. Patch by Jelle Zijlstra.
Add typing_extensions.Buffer, a marker class for buffer types, as proposed by PEP 688. Equivalent to collections.abc.Buffer in Python 3.12. Patch by Jelle Zijlstra.
Backport two CPython PRs fixing various issues with typing.Literal: https://github.com/python/cpython/pull/23294 and https://github.com/python/cpython/pull/23383. Both CPython PRs were originally by Yurii Karabas, and both were backported to Python >=3.9.1, but no earlier. Patch by Alex Waygood.
A side effect of one of the changes is that equality comparisons of Literal objects will now raise a TypeError if one of the Literal objects being compared has a mutable parameter. (Using mutable parameters with Literal is not supported by PEP 586 or by any major static type checkers.)
Literal is now reimplemented on all Python versions <= 3.10.0. The typing_extensions version does not suffer from the bug that was fixed in https://github.com/python/cpython/pull/29334. (The CPython bugfix was backported to CPython 3.10.1 and 3.9.8, but no earlier.)
Backport CPython PR 26067 (originally by Yurii Karabas), ensuring that isinstance() calls on protocols raise TypeError when the protocol is not decorated with @runtime_checkable. Patch by Alex Waygood.
Backport several significant performance improvements to runtime-checkable protocols that have been made in Python 3.12 (see https://github.com/python/cpython/issues/74690 for details). Patch by Alex Waygood.
A side effect of one of the performance improvements is that the members of a runtime-checkable protocol are now considered “frozen” at runtime as soon as the class has been created. Monkey-patching attributes onto a runtime-checkable protocol will still work, but will have no impact on isinstance() checks comparing objects to the protocol. See “What's New in Python 3.12” for more details.
isinstance() checks against runtime-checkable protocols now use inspect.getattr_static() rather than hasattr() to lookup whether attributes exist (backporting https://github.com/python/cpython/pull/103034). This means that descriptors and __getattr__ methods are no longer unexpectedly evaluated during isinstance() checks against runtime-checkable protocols. However, it may also mean that some objects which used to be considered instances of a runtime-checkable protocol on older versions of typing_extensions may no longer be considered instances of that protocol using the new release, and vice versa. Most users are unlikely to be affected by this change. Patch by Alex Waygood.
Backport the ability to define __init__ methods on Protocol classes, a change made in Python 3.11 (originally implemented in https://github.com/python/cpython/pull/31628 by Adrian Garcia Badaracco). Patch by Alex Waygood.
Speedup isinstance(3, typing_extensions.SupportsIndex) by >10x on Python <3.12. Patch by Alex Waygood.
Add typing_extensions versions of SupportsInt, SupportsFloat, SupportsComplex, SupportsBytes, SupportsAbs and SupportsRound. These have the same semantics as the versions from the typing module, but isinstance() checks against the typing_extensions versions are >10x faster at runtime on Python <3.12. Patch by Alex Waygood.
Add __orig_bases__ to non-generic TypedDicts, call-based TypedDicts, and call-based NamedTuples. Other TypedDicts and NamedTuples already had the attribute. Patch by Adrian Garcia Badaracco.
Add typing_extensions.get_original_bases, a backport of types.get_original_bases, introduced in Python 3.12 (CPython PR https://github.com/python/cpython/pull/101827, originally by James Hilton-Balfe). Patch by Alex Waygood.
This function should always produce correct results when called on classes constructed using features from typing_extensions. However, it may produce incorrect results when called on some NamedTuple or TypedDict classes that use typing.{NamedTuple,TypedDict} on Python <=3.11.
Constructing a call-based TypedDict using keyword arguments for the fields now causes a DeprecationWarning to be emitted. This matches the behaviour of typing.TypedDict on 3.11 and 3.12.
Backport the implementation of NewType from 3.10 (where it is implemented as a class rather than a function). This allows user-defined NewTypes to be pickled. Patch by Alex Waygood.
Fix tests and import on Python 3.12, where typing.TypeVar can no longer be subclassed. Patch by Jelle Zijlstra.
Add typing_extensions.TypeAliasType, a backport of typing.TypeAliasType from PEP 695. Patch by Jelle Zijlstra.
Backport changes to the repr of typing.Unpack that were made in order to implement PEP 692 (backport of https://github.com/python/cpython/pull/104048). Patch by Alex Waygood.
typing_extensions.deprecated. Patch by Jelle Zijlstra.default parameter, PEP 696. Enables runtime check if None was passed as default. Patch by Marc Mueller (@cdce8p).@typing_extensions.override decorator now sets the .__override__ attribute. Patch by Steven Troxler.get_type_hints() on cross-module inherited TypedDict in 3.9 and 3.10. Patch by Carl Meyer.frozen_default parameter on dataclass_transform. Patch by Erik De Bonte.typing_extensions.Any a backport of python 3.11's Any class which is subclassable at runtime. (backport from python/cpython#31841, by Shantanu and Jelle Zijlstra). Patch by James Hilton-Balfe (@Gobot1234).default parameter, PEP 696. Patch by Marc Mueller (@cdce8p).typing_extensions.override. Patch by Jelle Zijlstra.infer_variance parameter to TypeVar, as specified in PEP 695. Patch by Jelle Zijlstra.typing_extensions.NamedTuple, allowing for generic NamedTuples on Python <3.11 (backport from python/cpython#92027, by Serhiy Storchaka). Patch by Alex Waygood (@AlexWaygood).typing_extensions.TypedDict to allow for generic TypedDicts on Python <3.11 (backport from python/cpython#27663, by Samodya Abey). Patch by Alex Waygood (@AlexWaygood).typing.Unpack and typing.TypeVarTuple on Python 3.11.ParamSpecArgs and ParamSpecKwargs to __all__.typing_extensions.dataclass_transform to rename the field_descriptors parameter to field_specifiers and accept arbitrary keyword arguments.typing_extensions.get_overloads and typing_extensions.clear_overloads, and add registry support to typing_extensions.overload. Backport from python/cpython#89263.typing_extensions.assert_type. Backport from bpo-46480.typing_extensions on Python 3.7.0 and 3.7.1. Original patch by Nikita Sobolev (@sobolevn).typing_extensions.TypeVarTuple and typing_extensions.Unpack.Required and NotRequired with __required_keys__, __optional_keys__ and get_type_hints(). Patch by David Cabot (@d-k-bo).typing_extensions.LiteralString.Never and assert_never. Backport from bpo-46475.ParamSpec args and kwargs are now equal to themselves. Backport from bpo-46676. Patch by Gregory Beauregard (@GBeauregard).reveal_type. Backport from bpo-46414.typing_extensions.dataclass_transform.Annotated can now wrap ClassVar and Final. Backport from bpo-46491. Patch by Gregory Beauregard (@GBeauregard).Required and NotRequired to __all__. Patch by Yuri Karabas (@uriyyo).@final decorator now sets the __final__ attribute on the decorated object to allow runtime introspection. Backport from bpo-46342.is_typeddict. Patch by Chris Moradi (@chrismoradi) and James Hilton-Balfe (@Gobot1234).Required and NotRequired. Patch by Jelle Zijlstra (@jellezijlstra).Self as a type argument. Patch by Chris Wesseling (@CharString) and James Hilton-Balfe (@Gobot1234).typing_extensions.Self. Patch by James Hilton-Balfe (@Gobot1234).typing_extensions.Required and NotRequired. Patch by David Foster (@davidfstr).The following non-exported but non-private names have been removed as they are unneeded for supporting Python 3.6 and newer.
Prior to release 4.0.0 we did not provide a changelog. Please check the Git history for details.