Changes since 4.16.0rc1:

• Avoid a DeprecationWarning when deprecated is applied to a coroutine function on Python 3.14.0.

Changes since 4.15.0:

• Make typing_extensions.TypeAliasType's __module__ attribute writable. Backport of CPython PR #149172.
• Fix setting of __required_keys__ and __optional_keys__ when inheriting keys with the same name.
• Add support for AsyncIterator, io.Reader, io.Writer and os.PathLike protocols as bases for other protocols.
• Fix incorrect behaviour on Python 3.9 and Python 3.10 that meant that calling isinstance with typing_extensions.Concatenate[...] or typing_extensions.Unpack[...] as the first argument could have a different result in some situations depending on whether or not a profiling function had been set using sys.setprofile. This affected both CPython and PyPy implementations. Patch by Brian Schubert.
• Fix __init_subclass__() behavior in the presence of multiple inheritance involving an @deprecated-decorated base class. Backport of CPython PR #138210 by Brian Schubert.
• Raise TypeError when attempting to subclass typing_extensions.ParamSpec on Python 3.9. The typing implementation has always raised an error, and the typing_extensions implementation has raised an error on Python 3.10+ since typing_extensions v4.6.0. Patch by Brian Schubert.
• Add the bound, covariant, contravariant, and infer_variance parameters to TypeVarTuple.
• Officially support the bound, covariant, contravariant and infer_variance parameters to ParamSpec. Improve the validation of these parameters at runtime.
• Rename typing_extensions.Sentinel to typing_extensions.sentinel, following the name that has been adopted for builtins.sentinel on Python 3.15. typing_extensions.Sentinel is retained as a soft-deprecated alias for backwards compatibility.
• Add support for pickling sentinels.
• Sentinels now preserve their identity when copied or deep-copied.
• Deprecate passing name as a keyword argument or repr as a positional argument to the sentinel constructor.
• The default repr of a sentinel X = sentinel("X") is now X rather than <X>.
• Deprecate arbitrary attribute assignments to sentinels.
• Deprecate subclassing sentinels.
• Add support for Python 3.15.

• Make typing_extensions.TypeAliasType's __module__ attribute writable. Backport of CPython PR #149172.
• Fix setting of __required_keys__ and __optional_keys__ when inheriting keys with the same name.
• Add support for AsyncIterator, io.Reader, io.Writer and os.PathLike protocols as bases for other protocols.
• Fix incorrect behaviour on Python 3.9 and Python 3.10 that meant that calling isinstance with typing_extensions.Concatenate[...] or typing_extensions.Unpack[...] as the first argument could have a different result in some situations depending on whether or not a profiling function had been set using sys.setprofile. This affected both CPython and PyPy implementations. Patch by Brian Schubert.
• Fix __init_subclass__() behavior in the presence of multiple inheritance involving an @deprecated-decorated base class. Backport of CPython PR #138210 by Brian Schubert.
• Raise TypeError when attempting to subclass typing_extensions.ParamSpec on Python 3.9. The typing implementation has always raised an error, and the typing_extensions implementation has raised an error on Python 3.10+ since typing_extensions v4.6.0. Patch by Brian Schubert.
• Add the bound, covariant, contravariant, and infer_variance parameters to TypeVarTuple.
• Officially support the bound, covariant, contravariant and infer_variance parameters to ParamSpec. Improve the validation of these parameters at runtime.
• Rename typing_extensions.Sentinel to typing_extensions.sentinel, following the name that has been adopted for builtins.sentinel on Python 3.15. typing_extensions.Sentinel is retained as a soft-deprecated alias for backwards compatibility.
• Add support for pickling sentinels.
• Sentinels now preserve their identity when copied or deep-copied.
• Deprecate passing name as a keyword argument or repr as a positional argument to the sentinel constructor.
• The default repr of a sentinel X = sentinel("X") is now X rather than <X>.
• Deprecate arbitrary attribute assignments to sentinels.
• Deprecate subclassing sentinels.
• Add support for Python 3.15.

No user-facing changes since 4.15.0rc1.

New features since 4.14.1:

• Add the @typing_extensions.disjoint_base decorator, as specified
  in PEP 800. Patch by Jelle Zijlstra.
• Add typing_extensions.type_repr, a backport of
  annotationlib.type_repr,
  introduced in Python 3.14 (CPython PR #124551,
  originally by Jelle Zijlstra). Patch by Semyon Moroz.
• Fix behavior of type params in typing_extensions.evaluate_forward_ref. Backport of
  CPython PR #137227 by Jelle Zijlstra.

• Add the @typing_extensions.disjoint_base decorator, as specified
  in PEP 800. Patch by Jelle Zijlstra.
• Add typing_extensions.type_repr, a backport of
  annotationlib.type_repr,
  introduced in Python 3.14 (CPython PR #124551,
  originally by Jelle Zijlstra). Patch by Semyon Moroz.
• Fix behavior of type params in typing_extensions.evaluate_forward_ref. Backport of
  CPython PR #137227 by Jelle Zijlstra.

Release 4.14.1 (July 4, 2025)

• Fix usage of typing_extensions.TypedDict nested inside other types
  (e.g., typing.Type[typing_extensions.TypedDict]). This is not allowed by the
  type system but worked on older versions, so we maintain support.

This release adds several new features, including experimental support for inline typed dictionaries (PEP 764) and sentinels (PEP 661), and support for changes in Python 3.14. In addition, Python 3.8 is no longer supported.

Changes since 4.14.0rc1:

• Remove __or__ and __ror__ methods from typing_extensions.Sentinel
  on Python versions <3.10. PEP 604 was introduced in Python 3.10, and
  typing_extensions does not generally attempt to backport PEP-604 methods
  to prior versions.
• Further update typing_extensions.evaluate_forward_ref with changes in Python 3.14.

Changes included in 4.14.0rc1:

• Drop support for Python 3.8 (including PyPy-3.8). Patch by Victorien Plot.
• Do not attempt to re-export names that have been removed from typing,
  anticipating the removal of typing.no_type_check_decorator in Python 3.15.
  Patch by Jelle Zijlstra.
• Update typing_extensions.Format, typing_extensions.evaluate_forward_ref, and
  typing_extensions.TypedDict to align
  with changes in Python 3.14. Patches by Jelle Zijlstra.
• Fix tests for Python 3.14 and 3.15. Patches by Jelle Zijlstra.

New features:

• Add support for inline typed dictionaries (PEP 764).
  Patch by Victorien Plot.
• Add typing_extensions.Reader and typing_extensions.Writer. Patch by
  Sebastian Rittau.
• Add support for sentinels (PEP 661). Patch by
  Victorien Plot.

Major changes:

• Drop support for Python 3.8 (including PyPy-3.8). Patch by Victorien Plot.
• Do not attempt to re-export names that have been removed from typing,
  anticipating the removal of typing.no_type_check_decorator in Python 3.15.
  Patch by Jelle Zijlstra.
• Update typing_extensions.Format, typing_extensions.evaluate_forward_ref, and
  typing_extensions.TypedDict to align
  with changes in Python 3.14. Patches by Jelle Zijlstra.
• Fix tests for Python 3.14 and 3.15. Patches by Jelle Zijlstra.

New features:

• Add support for inline typed dictionaries (PEP 764).
  Patch by Victorien Plot.
• Add typing_extensions.Reader and typing_extensions.Writer. Patch by
  Sebastian Rittau.
• Add support for sentinels (PEP 661). Patch by
  Victorien Plot.

• Fix TypeError when taking the union of typing_extensions.TypeAliasType and a
  typing.TypeAliasType on Python 3.12 and 3.13.
  Patch by Joren Hammudoglu.
• Backport from CPython PR #132160
  to avoid having user arguments shadowed in generated __new__ by
  @typing_extensions.deprecated.
  Patch by Victorien Plot.

This is a bugfix release fixing two edge cases that appear on old bugfix releases of CPython.

Bugfixes:

• Fix regression in 4.13.0 on Python 3.10.2 causing a TypeError when using Concatenate.
  Patch by Daraan.
• Fix TypeError when using evaluate_forward_ref on Python 3.10.1-2 and 3.9.8-10.
  Patch by Daraan.

New features:

• Add typing_extensions.TypeForm from PEP 747. Patch by Jelle Zijlstra.
• Add typing_extensions.get_annotations, a backport of inspect.get_annotations that adds features specified by PEP 649. Patches by Jelle Zijlstra and Alex Waygood.
• Backport evaluate_forward_ref from CPython PR #119891 to evaluate ForwardRefs. Patch by Daraan, backporting a CPython PR by Jelle Zijlstra.

Bugfixes and changed features:

• Update PEP 728 implementation to a newer version of the PEP. Patch by Jelle Zijlstra.
• Copy the coroutine status of functions and methods wrapped with @typing_extensions.deprecated. Patch by Sebastian Rittau.
• Fix bug where TypeAliasType instances could be subscripted even where they were not generic. Patch by Daraan.
• Fix bug where a subscripted TypeAliasType instance did not have all attributes of the original TypeAliasType instance on older Python versions. Patch by Daraan and Alex Waygood.
• Fix bug where subscripted TypeAliasType instances (and some other subscripted objects) had wrong parameters if they were directly subscripted with an Unpack object. Patch by Daraan.
• Backport to Python 3.10 the ability to substitute ... in generic Callable aliases that have a Concatenate special form as their argument. Patch by Daraan.
• Extended the Concatenate backport for Python 3.8-3.10 to now accept Ellipsis as an argument. Patch by Daraan.
• Fix backport of get_type_hints to reflect Python 3.11+ behavior which does not add Union[..., NoneType] to annotations that have a None default value anymore. This fixes wrapping of Annotated in an unwanted Optional in such cases. Patch by Daraan.
• Fix error in subscription of Unpack aliases causing nested Unpacks to not be resolved correctly. Patch by Daraan.
• Backport CPython PR #124795: fix TypeAliasType not raising an error on non-tuple inputs for type_params. Patch by Daraan.
• Fix that lists and ... could not be used for parameter expressions for TypeAliasType instances before Python 3.11. Patch by Daraan.
• Fix error on Python 3.10 when using typing.Concatenate and typing_extensions.Concatenate together. Patch by Daraan.
• Backport of CPython PR #109544 to reflect Python 3.13+ behavior: A value assigned to __total__ in the class body of a TypedDict will be overwritten by the total argument of the TypedDict constructor. Patch by Daraan, backporting a CPython PR by Jelle Zijlstra.
• isinstance(typing_extensions.Unpack[...], TypeVar) now evaluates to False on Python 3.11 and newer, but remains True on versions before 3.11. Patch by Daraan.

New features:

• Add typing_extensions.TypeForm from PEP 747. Patch by Jelle Zijlstra.
• Add typing_extensions.get_annotations, a backport of inspect.get_annotations that adds features specified by PEP 649. Patches by Jelle Zijlstra and Alex Waygood.
• Backport evaluate_forward_ref from CPython PR #119891 to evaluate ForwardRefs. Patch by Daraan, backporting a CPython PR by Jelle Zijlstra.

Bugfixes and changed features:

• Update PEP 728 implementation to a newer version of the PEP. Patch by Jelle Zijlstra.
• Copy the coroutine status of functions and methods wrapped with @typing_extensions.deprecated. Patch by Sebastian Rittau.
• Fix bug where TypeAliasType instances could be subscripted even where they were not generic. Patch by Daraan.
• Fix bug where a subscripted TypeAliasType instance did not have all attributes of the original TypeAliasType instance on older Python versions. Patch by Daraan and Alex Waygood.
• Fix bug where subscripted TypeAliasType instances (and some other subscripted objects) had wrong parameters if they were directly subscripted with an Unpack object. Patch by Daraan.
• Backport to Python 3.10 the ability to substitute ... in generic Callable aliases that have a Concatenate special form as their argument. Patch by Daraan.
• Extended the Concatenate backport for Python 3.8-3.10 to now accept Ellipsis as an argument. Patch by Daraan.
• Fix backport of get_type_hints to reflect Python 3.11+ behavior which does not add Union[..., NoneType] to annotations that have a None default value anymore. This fixes wrapping of Annotated in an unwanted Optional in such cases. Patch by Daraan.
• Fix error in subscription of Unpack aliases causing nested Unpacks to not be resolved correctly. Patch by Daraan.
• Backport CPython PR #124795: fix TypeAliasType not raising an error on non-tuple inputs for type_params. Patch by Daraan.
• Fix that lists and ... could not be used for parameter expressions for TypeAliasType instances before Python 3.11. Patch by Daraan.
• Fix error on Python 3.10 when using typing.Concatenate and typing_extensions.Concatenate together. Patch by Daraan.
• Backport of CPython PR #109544 to reflect Python 3.13+ behavior: A value assigned to __total__ in the class body of a TypedDict will be overwritten by the total argument of the TypedDict constructor. Patch by Daraan, backporting a CPython PR by Jelle Zijlstra.
• Fix for Python 3.11 that now isinstance(typing_extensions.Unpack[...], TypeVar) evaluates to False, however still True for <3.11. Patch by Daraan

• Fix regression in v4.12.0 where specialization of certain generics with an overridden __eq__ method would raise errors. Patch by Jelle Zijlstra.
• Fix tests so they pass on 3.13.0b2

• Preliminary changes for compatibility with the draft implementation of PEP 649 in Python 3.14. Patch by Jelle Zijlstra.
• Fix regression in v4.12.0 where nested Annotated types would cause TypeError to be raised if the nested Annotated type had unhashable metadata. Patch by Alex Waygood.

This release focuses on compatibility with the upcoming release of Python 3.13. Most changes are related to the implementation of type parameter defaults (PEP 696).

Thanks to all of the people who contributed patches, especially Alex Waygood, who did most of the work adapting typing-extensions to the CPython PEP 696 implementation.

There is a single change since 4.12.0rc1:

• Fix incorrect behaviour of typing_extensions.ParamSpec on Python 3.8 and 3.9 that meant that isinstance(typing_extensions.ParamSpec("P"), typing.TypeVar) would have a different result in some situations depending on whether or not a profiling function had been set using sys.setprofile. Patch by Alex Waygood.

Changes included in 4.12.0rc1:

• Improve the implementation of type parameter defaults (PEP 696)
  • Backport the typing.NoDefault sentinel object from Python 3.13. TypeVars, ParamSpecs and TypeVarTuples without default values now have their __default__ attribute set to this sentinel value.
  • TypeVars, ParamSpecs and TypeVarTuples now have a has_default() method, matching typing.TypeVar, typing.ParamSpec and typing.TypeVarTuple on Python 3.13+.
  • TypeVars, ParamSpecs and TypeVarTuples with default=None passed to their constructors now have their __default__ attribute set to None at runtime rather than types.NoneType.
  • Fix most tests for TypeVar, ParamSpec and TypeVarTuple on Python 3.13.0b1 and newer.
  • Backport CPython PR #118774, allowing type parameters without default values to follow those with default values in some type parameter lists. Patch by Alex Waygood, backporting a CPython PR by Jelle Zijlstra.
  • It is now disallowed to use a TypeVar with a default value after a TypeVarTuple in a type parameter list. This matches the CPython implementation of PEP 696 on Python 3.13+.
  • Fix bug in PEP-696 implementation where a default value for a ParamSpec would be cast to a tuple if a list was provided. Patch by Alex Waygood.
• Fix Protocol tests on Python 3.13.0a6 and newer. 3.13.0a6 adds a new __static_attributes__ attribute to all classes in Python, which broke some assumptions made by the implementation of typing_extensions.Protocol. Similarly, 3.13.0b1 adds the new __firstlineno__ attribute to all classes.
• Fix AttributeError when using typing_extensions.runtime_checkable in combination with typing.Protocol on Python 3.12.2 or newer. Patch by Alex Waygood.
• At runtime, assert_never now includes the repr of the argument in the AssertionError. Patch by Hashem, backporting of the original fix https://github.com/python/cpython/pull/91720 by Jelle Zijlstra.
• The second and third parameters of typing_extensions.Generator, and the second parameter of typing_extensions.AsyncGenerator, now default to None. This matches the behaviour of typing.Generator and typing.AsyncGenerator on Python 3.13+.
• typing_extensions.ContextManager and typing_extensions.AsyncContextManager now have an optional second parameter, which defaults to Optional[bool]. The new parameter signifies the return type of the __(a)exit__ method, matching typing.ContextManager and typing.AsyncContextManager on Python 3.13+.
• Backport types.CapsuleType from Python 3.13.
• Releases are now made using Trusted Publishers improving the security of the release process. Patch by Jelle Zijlstra.

This release focuses on compatibility with the upcoming release of Python 3.13. Most changes are related to the implementation of type parameter defaults (PEP 696).

Thanks to all of the people who contributed patches, especially Alex Waygood, who did most of the work adapting typing-extensions to the CPython PEP 696 implementation.

Full changelog:

• Improve the implementation of type parameter defaults (PEP 696)
  • Backport the typing.NoDefault sentinel object from Python 3.13. TypeVars, ParamSpecs and TypeVarTuples without default values now have their __default__ attribute set to this sentinel value.
  • TypeVars, ParamSpecs and TypeVarTuples now have a has_default() method, matching typing.TypeVar, typing.ParamSpec and typing.TypeVarTuple on Python 3.13+.
  • TypeVars, ParamSpecs and TypeVarTuples with default=None passed to their constructors now have their __default__ attribute set to None at runtime rather than types.NoneType.
  • Fix most tests for TypeVar, ParamSpec and TypeVarTuple on Python 3.13.0b1 and newer.
  • Backport CPython PR #118774, allowing type parameters without default values to follow those with default values in some type parameter lists. Patch by Alex Waygood, backporting a CPython PR by Jelle Zijlstra.
  • It is now disallowed to use a TypeVar with a default value after a TypeVarTuple in a type parameter list. This matches the CPython implementation of PEP 696 on Python 3.13+.
  • Fix bug in PEP-696 implementation where a default value for a ParamSpec would be cast to a tuple if a list was provided. Patch by Alex Waygood.
• Fix Protocol tests on Python 3.13.0a6 and newer. 3.13.0a6 adds a new __static_attributes__ attribute to all classes in Python, which broke some assumptions made by the implementation of typing_extensions.Protocol. Similarly, 3.13.0b1 adds the new __firstlineno__ attribute to all classes.
• Fix AttributeError when using typing_extensions.runtime_checkable in combination with typing.Protocol on Python 3.12.2 or newer. Patch by Alex Waygood.
• At runtime, assert_never now includes the repr of the argument in the AssertionError. Patch by Hashem, backporting of the original fix https://github.com/python/cpython/pull/91720 by Jelle Zijlstra.
• The second and third parameters of typing_extensions.Generator, and the second parameter of typing_extensions.AsyncGenerator, now default to None. This matches the behaviour of typing.Generator and typing.AsyncGenerator on Python 3.13+.
• typing_extensions.ContextManager and typing_extensions.AsyncContextManager now have an optional second parameter, which defaults to Optional[bool]. The new parameter signifies the return type of the __(a)exit__ method, matching typing.ContextManager and typing.AsyncContextManager on Python 3.13+.
• Backport types.CapsuleType from Python 3.13.
• Releases are now made using Trusted Publishers improving the security of the release process. Patch by Jelle Zijlstra.

This is another alpha release to test the new release workflow.

Release 4.11.0 (April 5, 2024)

This feature release provides improvements to various recently added features, most importantly type parameter defaults (PEP 696).

There are no changes since 4.11.0rc1.

Changes since 4.10.0:

• Fix tests on Python 3.13.0a5. Patch by Jelle Zijlstra.
• Fix the runtime behavior of type parameters with defaults (PEP 696). Patch by Nadir Chowdhury.
• Fix minor discrepancy between error messages produced by typing and typing_extensions on Python 3.10. Patch by Jelle Zijlstra.
• When include_extra=False, get_type_hints() now strips ReadOnly from the annotation.

• Fix tests on Python 3.13.0a5. Patch by Jelle Zijlstra.
• Fix the runtime behavior of type parameters with defaults (PEP 696). Patch by Nadir Chowdhury.
• Fix minor discrepancy between error messages produced by typing and typing_extensions on Python 3.10. Patch by Jelle Zijlstra.
• When include_extra=False, get_type_hints() now strips ReadOnly from the annotation.

Release 4.10.0 (February 25, 2024)

This feature release adds support for PEP 728 (TypedDict with extra items) and PEP 742 (TypeIs).

There are no changes since 4.10.0rc1.

Release 4.10.0rc1 (February 17, 2024)

• Add support for PEP 728, supporting the closed keyword argument and the special __extra_items__ key for TypedDict. Patch by Zixuan James Li.
• Add support for PEP 742, adding typing_extensions.TypeIs. Patch by Jelle Zijlstra.
• Drop runtime error when a read-only TypedDict item overrides a mutable one. Type checkers should still flag this as an error. Patch by Jelle Zijlstra.
• Speedup issubclass() checks against simple runtime-checkable protocols by around 6% (backporting https://github.com/python/cpython/pull/112717, by Alex Waygood).
• Fix a regression in the implementation of protocols where typing.Protocol classes that were not marked as @runtime_checkable would be unnecessarily introspected, potentially causing exceptions to be raised if the protocol had problematic members. Patch by Alex Waygood, backporting https://github.com/python/cpython/pull/113401.

This feature release adds typing_extensions.ReadOnly, as specified by PEP 705, and makes various other improvements, especially to @typing_extensions.deprecated().

There are no changes since 4.9.0rc1.

• Add support for PEP 705, adding typing_extensions.ReadOnly. Patch by Jelle Zijlstra.
• All parameters on NewType.__call__ are now positional-only. This means that the signature of typing_extensions.NewType.__call__ now exactly matches the signature of typing.NewType.__call__. Patch by Alex Waygood.
• Fix bug with using @deprecated on a mixin class. Inheriting from a deprecated class now raises a DeprecationWarning. Patch by Jelle Zijlstra.
• @deprecated now gives a better error message if you pass a non-str argument to the msg parameter. Patch by Alex Waygood.
• @deprecated is now implemented as a class for better introspectability. Patch by Jelle Zijlstra.
• Exclude __match_args__ from Protocol members. Backport of https://github.com/python/cpython/pull/110683 by Nikita Sobolev.
• When creating a typing_extensions.NamedTuple class, ensure __set_name__ is called on all objects that define __set_name__ and exist in the values of the NamedTuple class's class dictionary. Patch by Alex Waygood, backporting https://github.com/python/cpython/pull/111876.
• Improve the error message when trying to call issubclass() against a Protocol that has non-method members. Patch by Alex Waygood (backporting https://github.com/python/cpython/pull/112344, by Randolph Scholz).

Changes since 4.7.1:

• Add typing_extensions.Doc, as proposed by PEP 727. Patch by Sebastián Ramírez.
• Drop support for Python 3.7 (including PyPy-3.7). Patch by Alex Waygood.
• Fix bug where get_original_bases() would return incorrect results when called on a concrete subclass of a generic class. Patch by Alex Waygood (backporting https://github.com/python/cpython/pull/107584, by James Hilton-Balfe).
• Fix bug where ParamSpec(default=...) would raise a TypeError on Python versions <3.11. Patch by James Hilton-Balfe

No changes since 4.8.0rc1.

• Add typing_extensions.Doc, as proposed by PEP 727. Patch by Sebastián Ramírez.
• Drop support for Python 3.7 (including PyPy-3.7). Patch by Alex Waygood.
• Fix bug where get_original_bases() would return incorrect results when called on a concrete subclass of a generic class. Patch by Alex Waygood (backporting https://github.com/python/cpython/pull/107584, by James Hilton-Balfe).
• Fix bug where ParamSpec(default=...) would raise a TypeError on Python versions <3.11. Patch by James Hilton-Balfe

• Fix support for TypedDict, NamedTuple and is_protocol on PyPy-3.7 and PyPy-3.8. Patch by Alex Waygood. Note that PyPy-3.7 and PyPy-3.8 are unsupported by the PyPy project. The next feature release of typing-extensions will drop support for PyPy-3.7 and may also drop support for PyPy-3.8.

This is a feature release. Major changes include:

• All non-deprecated names from typing are now re-exported by typing_extensions for convenience
• Add typing_extensions.get_protocol_members and typing_extensions.is_protocol
• Declare support for Python 3.12
• This will be the last feature release to support Python 3.7, which recently reached its end-of-life

Full changelog of versions 4.7.0 and 4.7.0rc1:

Release 4.7.0 (June 28, 2023)

• This is expected to be the last feature release supporting Python 3.7, which reaches its end of life on June 27, 2023. Version 4.8.0 will support only Python 3.8.0 and up.
• Fix bug where a typing_extensions.Protocol class that had one or more non-callable members would raise TypeError when issubclass() was called against it, even if it defined a custom __subclasshook__ method. The correct behaviour -- which has now been restored -- is not to raise TypeError in these situations if a custom __subclasshook__ method is defined. Patch by Alex Waygood (backporting https://github.com/python/cpython/pull/105976).

Release 4.7.0rc1 (June 21, 2023)

• Add 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.
• Due to changes in the implementation of 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).
• Align the implementation of 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.
• Declare support for Python 3.12. Patch by Jelle Zijlstra.
• Fix tests on Python 3.13, which removes support for creating TypedDict classes through the keyword-argument syntax. Patch by Jelle Zijlstra.
• Fix a regression introduced in v4.6.3 that meant that issubclass(object, typing_extensions.Protocol) would erroneously raise TypeError. Patch by Alex Waygood (backporting the CPython PR https://github.com/python/cpython/pull/105239).
• Allow 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).
• Allow classes to inherit from both 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.
• Backport several deprecations from CPython relating to unusual ways to create TypedDicts and NamedTuples. CPython PRs #105609 and #105780 by Alex Waygood; typing_extensions backport by Jelle Zijlstra.
  • Creating a NamedTuple using the functional syntax with keyword arguments (NT = NamedTuple("NT", a=int)) is now deprecated.
  • Creating a NamedTuple with zero fields using the syntax NT = NamedTuple("NT") or NT = NamedTuple("NT", None) is now deprecated.
  • Creating a TypedDict with zero fields using the syntax TD = TypedDict("TD") or TD = TypedDict("TD", None) is now deprecated.
• Fix bug on Python 3.7 where a protocol 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).

This is a pre-release; please test it! 4.7.0 final is expected in one week (June 28).

Changelog:

• Add 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.
• Due to changes in the implementation of 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).
• Align the implementation of 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.
• Declare support for Python 3.12. Patch by Jelle Zijlstra.
• Fix tests on Python 3.13, which removes support for creating TypedDict classes through the keyword-argument syntax. Patch by Jelle Zijlstra.
• Fix a regression introduced in v4.6.3 that meant that issubclass(object, typing_extensions.Protocol) would erroneously raise TypeError. Patch by Alex Waygood (backporting the CPython PR https://github.com/python/cpython/pull/105239).
• Allow 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).
• Allow classes to inherit from both 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.
• Backport several deprecations from CPython relating to unusual ways to create TypedDicts and NamedTuples. CPython PRs #105609 and #105780 by Alex Waygood; typing_extensions backport by Jelle Zijlstra.
  • Creating a NamedTuple using the functional syntax with keyword arguments (NT = NamedTuple("NT", a=int)) is now deprecated.
  • Creating a NamedTuple with zero fields using the syntax NT = NamedTuple("NT") or NT = NamedTuple("NT", None) is now deprecated.
  • Creating a TypedDict with zero fields using the syntax TD = TypedDict("TD") or TD = TypedDict("TD", None) is now deprecated.
• Fix bug on Python 3.7 where a protocol 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).

• Fix a regression introduced in v4.6.0 in the implementation of runtime-checkable protocols. The regression meant that doing 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).
• Sync the repository's LICENSE file with that of CPython. typing_extensions is distributed under the same license as CPython itself.
• Skip a problematic test on Python 3.12.0b1. The test fails on 3.12.0b1 due to a bug in CPython, which will be fixed in 3.12.0b2. The typing_extensions test suite now passes on 3.12.0b1.

• Fix use of @deprecated on classes with __new__ but no __init__. Patch by Jelle Zijlstra.
• Fix regression in version 4.6.1 where comparing a generic class against a runtime-checkable protocol using isinstance() would cause AttributeError to be raised if using Python 3.7.

• Change deprecated @runtime to formal API @runtime_checkable in the error message. Patch by Xuehai Pan.
• Fix regression in 4.6.0 where attempting to define a 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.

• Runtime support for PEP 702, adding typing_extensions.deprecated. Patch by Jelle Zijlstra.
• Add better default value for TypeVar default parameter, PEP 696. Enables runtime check if None was passed as default. Patch by Marc Mueller (@cdce8p).
• The @typing_extensions.override decorator now sets the .__override__ attribute. Patch by Steven Troxler.
• Fix get_type_hints() on cross-module inherited TypedDict in 3.9 and 3.10. Patch by Carl Meyer.
• Add frozen_default parameter on dataclass_transform. Patch by Erik De Bonte.

• Add 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).
• Add initial support for TypeVarLike default parameter, PEP 696. Patch by Marc Mueller (@cdce8p).
• Runtime support for PEP 698, adding typing_extensions.override. Patch by Jelle Zijlstra.
• Add the infer_variance parameter to TypeVar, as specified in PEP 695. Patch by Jelle Zijlstra.

• Add typing_extensions.NamedTuple, allowing for generic NamedTuples on Python <3.11 (backport from python/cpython#92027, by Serhiy Storchaka). Patch by Alex Waygood (@AlexWaygood).
• Adjust 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).

• Re-export typing.Unpack and typing.TypeVarTuple on Python 3.11.
• Add ParamSpecArgs and ParamSpecKwargs to __all__.
• Improve "accepts only single type" error messages.
• Improve the distributed package. Patch by Marc Mueller (@cdce8p).
• Update typing_extensions.dataclass_transform to rename the field_descriptors parameter to field_specifiers and accept arbitrary keyword arguments.
• Add typing_extensions.get_overloads and typing_extensions.clear_overloads, and add registry support to typing_extensions.overload. Backport from python/cpython#89263.
• Add typing_extensions.assert_type. Backport from bpo-46480.
• Drop support for Python 3.6. Original patch by Adam Turner (@AA-Turner).

• Fix importing typing_extensions on Python 3.7.0 and 3.7.1. Original patch by Nikita Sobolev (@sobolevn).

• Runtime support for PEP 646, adding typing_extensions.TypeVarTuple and typing_extensions.Unpack.
• Add interaction of Required and NotRequired with __required_keys__, __optional_keys__ and get_type_hints(). Patch by David Cabot (@d-k-bo).
• Runtime support for PEP 675 and typing_extensions.LiteralString.
• Add 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).
• Add reveal_type. Backport from bpo-46414.
• Runtime support for PEP 681 and typing_extensions.dataclass_transform.
• Annotated can now wrap ClassVar and Final. Backport from bpo-46491. Patch by Gregory Beauregard (@GBeauregard).
• Add missed Required and NotRequired to __all__. Patch by Yuri Karabas (@uriyyo).
• The @final decorator now sets the __final__ attribute on the decorated object to allow runtime introspection. Backport from bpo-46342.
• Add is_typeddict. Patch by Chris Moradi (@chrismoradi) and James Hilton-Balfe (@Gobot1234).

• Fix broken sdist in release 4.0.0. Patch by Adam Turner (@AA-Turner).
• Fix equality comparison for Required and NotRequired. Patch by Jelle Zijlstra (@jellezijlstra).
• Fix usage of Self as a type argument. Patch by Chris Wesseling (@CharString) and James Hilton-Balfe (@Gobot1234).

• Starting with version 4.0.0, typing_extensions uses Semantic Versioning. See the README for more information.
• Dropped support for Python versions 3.5 and older, including Python 2.7.
• Simplified backports for Python 3.6.0 and newer. Patch by Adam Turner (@AA-Turner).

Added in version 4.0.0

• Runtime support for PEP 673 and typing_extensions.Self. Patch by James Hilton-Balfe (@Gobot1234).
• Runtime support for PEP 655 and typing_extensions.Required and NotRequired. Patch by David Foster (@davidfstr).

Removed in version 4.0.0

The following non-exported but non-private names have been removed as they are unneeded for supporting Python 3.6 and newer.

• TypingMeta
• OLD_GENERICS
• SUBS_TREE
• HAVE_ANNOTATED
• HAVE_PROTOCOLS
• V_co
• VT_co