From d0cdb55af1370163d9fdb546a1865c93cd155686 Mon Sep 17 00:00:00 2001 From: L2501 Date: Wed, 16 Aug 2023 07:38:26 +0000 Subject: [PATCH] [script.module.typing_extensions] 4.7.1 --- .../{LICENSE => LICENSE.txt} | 53 +- script.module.typing_extensions/README | 90 - script.module.typing_extensions/addon.xml | 20 +- .../lib/typing_extensions.py | 4414 ++++++++++------- .../{ => resources}/icon.png | Bin 5 files changed, 2706 insertions(+), 1871 deletions(-) rename script.module.typing_extensions/{LICENSE => LICENSE.txt} (85%) delete mode 100644 script.module.typing_extensions/README rename script.module.typing_extensions/{ => resources}/icon.png (100%) diff --git a/script.module.typing_extensions/LICENSE b/script.module.typing_extensions/LICENSE.txt similarity index 85% rename from script.module.typing_extensions/LICENSE rename to script.module.typing_extensions/LICENSE.txt index 583f9f6e61..f26bcf4d2d 100644 --- a/script.module.typing_extensions/LICENSE +++ b/script.module.typing_extensions/LICENSE.txt @@ -2,25 +2,24 @@ A. HISTORY OF THE SOFTWARE ========================== Python was created in the early 1990s by Guido van Rossum at Stichting -Mathematisch Centrum (CWI, see http://www.cwi.nl) in the Netherlands +Mathematisch Centrum (CWI, see https://www.cwi.nl) in the Netherlands as a successor of a language called ABC. Guido remains Python's principal author, although it includes many contributions from others. In 1995, Guido continued his work on Python at the Corporation for -National Research Initiatives (CNRI, see http://www.cnri.reston.va.us) +National Research Initiatives (CNRI, see https://www.cnri.reston.va.us) in Reston, Virginia where he released several versions of the software. In May 2000, Guido and the Python core development team moved to BeOpen.com to form the BeOpen PythonLabs team. In October of the same -year, the PythonLabs team moved to Digital Creations (now Zope -Corporation, see http://www.zope.com). In 2001, the Python Software -Foundation (PSF, see http://www.python.org/psf/) was formed, a -non-profit organization created specifically to own Python-related -Intellectual Property. Zope Corporation is a sponsoring member of -the PSF. - -All Python releases are Open Source (see http://www.opensource.org for +year, the PythonLabs team moved to Digital Creations, which became +Zope Corporation. In 2001, the Python Software Foundation (PSF, see +https://www.python.org/psf/) was formed, a non-profit organization +created specifically to own Python-related Intellectual Property. +Zope Corporation was a sponsoring member of the PSF. + +All Python releases are Open Source (see https://opensource.org for the Open Source Definition). Historically, most, but not all, Python releases have also been GPL-compatible; the table below summarizes the various releases. @@ -60,6 +59,17 @@ direction to make these releases possible. B. TERMS AND CONDITIONS FOR ACCESSING OR OTHERWISE USING PYTHON =============================================================== +Python software and documentation are licensed under the +Python Software Foundation License Version 2. + +Starting with Python 3.8.6, examples, recipes, and other code in +the documentation are dual licensed under the PSF License Version 2 +and the Zero-Clause BSD license. + +Some software incorporated into Python is under different licenses. +The licenses are listed with code falling under that license. + + PYTHON SOFTWARE FOUNDATION LICENSE VERSION 2 -------------------------------------------- @@ -74,8 +84,9 @@ analyze, test, perform and/or display publicly, prepare derivative works, distribute, and otherwise use Python alone or in any derivative version, provided, however, that PSF's License Agreement and PSF's notice of copyright, i.e., "Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, -2011, 2012, 2013, 2014 Python Software Foundation; All Rights Reserved" are -retained in Python alone or in any derivative version prepared by Licensee. +2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023 Python Software Foundation; +All Rights Reserved" are retained in Python alone or in any derivative version +prepared by Licensee. 3. In the event Licensee prepares a derivative work that is based on or incorporates Python or any part thereof, and wants to make @@ -180,9 +191,9 @@ version prepared by Licensee. Alternately, in lieu of CNRI's License Agreement, Licensee may substitute the following text (omitting the quotes): "Python 1.6.1 is made available subject to the terms and conditions in CNRI's License Agreement. This Agreement together with -Python 1.6.1 may be located on the Internet using the following +Python 1.6.1 may be located on the internet using the following unique, persistent identifier (known as a handle): 1895.22/1013. This -Agreement may also be obtained from a proxy server on the Internet +Agreement may also be obtained from a proxy server on the internet using the following URL: http://hdl.handle.net/1895.22/1013". 3. In the event Licensee prepares a derivative work that is based on @@ -252,3 +263,17 @@ FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + +ZERO-CLAUSE BSD LICENSE FOR CODE IN THE PYTHON DOCUMENTATION +---------------------------------------------------------------------- + +Permission to use, copy, modify, and/or distribute this software for any +purpose with or without fee is hereby granted. + +THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH +REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY +AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, +INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM +LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR +OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR +PERFORMANCE OF THIS SOFTWARE. diff --git a/script.module.typing_extensions/README b/script.module.typing_extensions/README deleted file mode 100644 index 5256bbc1f7..0000000000 --- a/script.module.typing_extensions/README +++ /dev/null @@ -1,90 +0,0 @@ -================= -Typing Extensions -================= - -.. image:: https://badges.gitter.im/python/typing.svg - :alt: Chat at https://gitter.im/python/typing - :target: https://gitter.im/python/typing?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge - -Overview -======== - -The ``typing`` module was added to the standard library in Python 3.5 on -a provisional basis and will no longer be provisional in Python 3.7. However, -this means users of Python 3.5 - 3.6 who are unable to upgrade will not be -able to take advantage of new types added to the ``typing`` module, such as -``typing.Text`` or ``typing.Coroutine``. - -The ``typing_extensions`` module contains both backports of these changes -as well as experimental types that will eventually be added to the ``typing`` -module, such as ``Protocol`` (see PEP 544 for details about protocols and -static duck typing) or ``TypedDict`` (see PEP 589). - -Users of other Python versions should continue to install and use -use the ``typing`` module from PyPi instead of using this one unless -specifically writing code that must be compatible with multiple Python -versions or requires experimental types. - -Included items -============== - -This module currently contains the following: - -All Python versions: --------------------- - -- ``ClassVar`` -- ``ContextManager`` -- ``Counter`` -- ``DefaultDict`` -- ``Deque`` -- ``final`` -- ``Final`` -- ``Literal`` -- ``NewType`` -- ``NoReturn`` -- ``overload`` (note that older versions of ``typing`` only let you use ``overload`` in stubs) -- ``Protocol`` (except on Python 3.5.0) -- ``runtime`` (except on Python 3.5.0) -- ``Text`` -- ``Type`` -- ``TypedDict`` -- ``TYPE_CHECKING`` - -Python 3.4+ only: ------------------ - -- ``ChainMap`` - -Python 3.5+ only: ------------------ - -- ``AsyncIterable`` -- ``AsyncIterator`` -- ``AsyncContextManager`` -- ``Awaitable`` -- ``Coroutine`` - -Python 3.6+ only: ------------------ - -- ``AsyncGenerator`` - -Other Notes and Limitations -=========================== - -There are a few types whose interface was modified between different -versions of typing. For example, ``typing.Sequence`` was modified to -subclass ``typing.Reversible`` as of Python 3.5.3. - -These changes are _not_ backported to prevent subtle compatibility -issues when mixing the differing implementations of modified classes. - -Running tests -============= - -To run tests, navigate into the appropriate source directory and run -``test_typing_extensions.py``. You will also need to install the latest -version of ``typing`` if you are using a version of Python that does not -include ``typing`` as a part of the standard library. - diff --git a/script.module.typing_extensions/addon.xml b/script.module.typing_extensions/addon.xml index c30926e41e..bea47e47e4 100644 --- a/script.module.typing_extensions/addon.xml +++ b/script.module.typing_extensions/addon.xml @@ -1,22 +1,18 @@ - + - + - + - Typing Extensions – Backported and Experimental Type Hints for Python - Packed for Kodi from https://github.com/python/typing/blob/master/typing_extensions/ + Backported and Experimental Type Hints for Python 3.7+ + Backported and Experimental Type Hints for Python 3.7+ all PSF-2.0 - https://github.com/Razzeee/script.module.typing_extensions - + https://typing-extensions.readthedocs.io/en/latest/ + https://github.com/python/typing_extensions - icon.png + resources/icon.png diff --git a/script.module.typing_extensions/lib/typing_extensions.py b/script.module.typing_extensions/lib/typing_extensions.py index a6f4281b25..901f3b967c 100644 --- a/script.module.typing_extensions/lib/typing_extensions.py +++ b/script.module.typing_extensions/lib/typing_extensions.py @@ -1,222 +1,205 @@ import abc import collections -import contextlib +import collections.abc +import functools +import inspect +import operator import sys +import types as _types import typing -import collections.abc as collections_abc -import operator - -# These are used by Protocol implementation -# We use internal typing helpers here, but this significantly reduces -# code duplication. (Also this is only until Protocol is in typing.) -from typing import Generic, Callable, TypeVar, Tuple - -# After PEP 560, internal typing API was substantially reworked. -# This is especially important for Protocol class which uses internal APIs -# quite extensivelly. -PEP_560 = sys.version_info[:3] >= (3, 7, 0) - -if PEP_560: - GenericMeta = TypingMeta = type -else: - from typing import GenericMeta, TypingMeta -OLD_GENERICS = False -try: - from typing import _type_vars, _next_in_mro, _type_check -except ImportError: - OLD_GENERICS = True -try: - from typing import _subs_tree # noqa - SUBS_TREE = True -except ImportError: - SUBS_TREE = False -try: - from typing import _tp_cache -except ImportError: - def _tp_cache(x): - return x -try: - from typing import _TypingEllipsis, _TypingEmpty -except ImportError: - class _TypingEllipsis: - pass - - class _TypingEmpty: - pass - - -# The two functions below are copies of typing internal helpers. -# They are needed by _ProtocolMeta - - -def _no_slots_copy(dct): - dict_copy = dict(dct) - if '__slots__' in dict_copy: - for slot in dict_copy['__slots__']: - dict_copy.pop(slot, None) - return dict_copy - - -def _check_generic(cls, parameters): - if not cls.__parameters__: - raise TypeError("%s is not a generic class" % repr(cls)) - alen = len(parameters) - elen = len(cls.__parameters__) - if alen != elen: - raise TypeError("Too %s parameters for %s; actual %s, expected %s" % - ("many" if alen > elen else "few", repr(cls), alen, elen)) - - -if hasattr(typing, '_generic_new'): - _generic_new = typing._generic_new -else: - # Note: The '_generic_new(...)' function is used as a part of the - # process of creating a generic type and was added to the typing module - # as of Python 3.5.3. - # - # We've defined '_generic_new(...)' below to exactly match the behavior - # implemented in older versions of 'typing' bundled with Python 3.5.0 to - # 3.5.2. This helps eliminate redundancy when defining collection types - # like 'Deque' later. - # - # See https://github.com/python/typing/pull/308 for more details -- in - # particular, compare and contrast the definition of types like - # 'typing.List' before and after the merge. - - def _generic_new(base_cls, cls, *args, **kwargs): - return base_cls.__new__(cls, *args, **kwargs) - -# See https://github.com/python/typing/pull/439 -if hasattr(typing, '_geqv'): - from typing import _geqv - _geqv_defined = True -else: - _geqv = None - _geqv_defined = False - -if sys.version_info[:2] >= (3, 6): - import _collections_abc - _check_methods_in_mro = _collections_abc._check_methods -else: - def _check_methods_in_mro(C, *methods): - mro = C.__mro__ - for method in methods: - for B in mro: - if method in B.__dict__: - if B.__dict__[method] is None: - return NotImplemented - break - else: - return NotImplemented - return True - +import warnings -# Please keep __all__ alphabetized within each category. __all__ = [ # Super-special typing primitives. + 'Any', 'ClassVar', + 'Concatenate', 'Final', + 'LiteralString', + 'ParamSpec', + 'ParamSpecArgs', + 'ParamSpecKwargs', + 'Self', 'Type', + 'TypeVar', + 'TypeVarTuple', + 'Unpack', # ABCs (from collections.abc). - # The following are added depending on presence - # of their non-generic counterparts in stdlib: - # 'Awaitable', - # 'AsyncIterator', - # 'AsyncIterable', - # 'Coroutine', - # 'AsyncGenerator', - # 'AsyncContextManager', - # 'ChainMap', + 'Awaitable', + 'AsyncIterator', + 'AsyncIterable', + 'Coroutine', + 'AsyncGenerator', + 'AsyncContextManager', + 'Buffer', + 'ChainMap', # Concrete collection types. 'ContextManager', 'Counter', 'Deque', 'DefaultDict', + 'NamedTuple', + 'OrderedDict', 'TypedDict', # Structural checks, a.k.a. protocols. + 'SupportsAbs', + 'SupportsBytes', + 'SupportsComplex', + 'SupportsFloat', 'SupportsIndex', + 'SupportsInt', + 'SupportsRound', # One-off things. + 'Annotated', + 'assert_never', + 'assert_type', + 'clear_overloads', + 'dataclass_transform', + 'deprecated', + 'get_overloads', 'final', + 'get_args', + 'get_origin', + 'get_original_bases', + 'get_protocol_members', + 'get_type_hints', 'IntVar', + 'is_protocol', + 'is_typeddict', 'Literal', 'NewType', 'overload', + 'override', + 'Protocol', + 'reveal_type', + 'runtime', + 'runtime_checkable', 'Text', + 'TypeAlias', + 'TypeAliasType', + 'TypeGuard', 'TYPE_CHECKING', + 'Never', + 'NoReturn', + 'Required', + 'NotRequired', + + # Pure aliases, have always been in typing + 'AbstractSet', + 'AnyStr', + 'BinaryIO', + 'Callable', + 'Collection', + 'Container', + 'Dict', + 'ForwardRef', + 'FrozenSet', + 'Generator', + 'Generic', + 'Hashable', + 'IO', + 'ItemsView', + 'Iterable', + 'Iterator', + 'KeysView', + 'List', + 'Mapping', + 'MappingView', + 'Match', + 'MutableMapping', + 'MutableSequence', + 'MutableSet', + 'Optional', + 'Pattern', + 'Reversible', + 'Sequence', + 'Set', + 'Sized', + 'TextIO', + 'Tuple', + 'Union', + 'ValuesView', + 'cast', + 'no_type_check', + 'no_type_check_decorator', ] -# Annotated relies on substitution trees of pep 560. It will not work for -# versions of typing older than 3.5.3 -HAVE_ANNOTATED = PEP_560 or SUBS_TREE - -if PEP_560: - __all__.extend(["get_args", "get_origin", "get_type_hints"]) - -if HAVE_ANNOTATED: - __all__.append("Annotated") - -# Protocols are hard to backport to the original version of typing 3.5.0 -HAVE_PROTOCOLS = sys.version_info[:3] != (3, 5, 0) - -if HAVE_PROTOCOLS: - __all__.extend(['Protocol', 'runtime', 'runtime_checkable']) +# for backward compatibility +PEP_560 = True +GenericMeta = type +# The functions below are modified copies of typing internal helpers. +# They are needed by _ProtocolMeta and they provide support for PEP 646. -# TODO -if hasattr(typing, 'NoReturn'): - NoReturn = typing.NoReturn -elif hasattr(typing, '_FinalTypingBase'): - class _NoReturn(typing._FinalTypingBase, _root=True): - """Special type indicating functions that never return. - Example:: - - from typing import NoReturn - def stop() -> NoReturn: - raise Exception('no way') +class _Sentinel: + def __repr__(self): + return "" - This type is invalid in other positions, e.g., ``List[NoReturn]`` - will fail in static type checkers. - """ - __slots__ = () - def __instancecheck__(self, obj): - raise TypeError("NoReturn cannot be used with isinstance().") +_marker = _Sentinel() - def __subclasscheck__(self, cls): - raise TypeError("NoReturn cannot be used with issubclass().") - NoReturn = _NoReturn(_root=True) +def _check_generic(cls, parameters, elen=_marker): + """Check correct count for parameters of a generic cls (internal helper). + This gives a nice error message in case of count mismatch. + """ + if not elen: + raise TypeError(f"{cls} is not a generic class") + if elen is _marker: + if not hasattr(cls, "__parameters__") or not cls.__parameters__: + raise TypeError(f"{cls} is not a generic class") + elen = len(cls.__parameters__) + alen = len(parameters) + if alen != elen: + if hasattr(cls, "__parameters__"): + parameters = [p for p in cls.__parameters__ if not _is_unpack(p)] + num_tv_tuples = sum(isinstance(p, TypeVarTuple) for p in parameters) + if (num_tv_tuples > 0) and (alen >= elen - num_tv_tuples): + return + raise TypeError(f"Too {'many' if alen > elen else 'few'} parameters for {cls};" + f" actual {alen}, expected {elen}") + + +if sys.version_info >= (3, 10): + def _should_collect_from_parameters(t): + return isinstance( + t, (typing._GenericAlias, _types.GenericAlias, _types.UnionType) + ) +elif sys.version_info >= (3, 9): + def _should_collect_from_parameters(t): + return isinstance(t, (typing._GenericAlias, _types.GenericAlias)) else: - class _NoReturnMeta(typing.TypingMeta): - """Metaclass for NoReturn""" - def __new__(cls, name, bases, namespace, _root=False): - return super().__new__(cls, name, bases, namespace, _root=_root) - - def __instancecheck__(self, obj): - raise TypeError("NoReturn cannot be used with isinstance().") - - def __subclasscheck__(self, cls): - raise TypeError("NoReturn cannot be used with issubclass().") + def _should_collect_from_parameters(t): + return isinstance(t, typing._GenericAlias) and not t._special - class NoReturn(typing.Final, metaclass=_NoReturnMeta, _root=True): - """Special type indicating functions that never return. - Example:: - - from typing import NoReturn - def stop() -> NoReturn: - raise Exception('no way') - - This type is invalid in other positions, e.g., ``List[NoReturn]`` - will fail in static type checkers. - """ - __slots__ = () +def _collect_type_vars(types, typevar_types=None): + """Collect all type variable contained in types in order of + first appearance (lexicographic order). For example:: + _collect_type_vars((T, List[S, T])) == (T, S) + """ + if typevar_types is None: + typevar_types = typing.TypeVar + tvars = [] + for t in types: + if ( + isinstance(t, typevar_types) and + t not in tvars and + not _is_unpack(t) + ): + tvars.append(t) + if _should_collect_from_parameters(t): + tvars.extend([t for t in t.__parameters__ if t not in tvars]) + return tuple(tvars) + + +NoReturn = typing.NoReturn # Some unconstrained type variables. These are used by the container types. # (These are not for export.) @@ -224,152 +207,58 @@ def stop() -> NoReturn: KT = typing.TypeVar('KT') # Key type. VT = typing.TypeVar('VT') # Value type. T_co = typing.TypeVar('T_co', covariant=True) # Any type covariant containers. -V_co = typing.TypeVar('V_co', covariant=True) # Any type covariant containers. -VT_co = typing.TypeVar('VT_co', covariant=True) # Value type covariant containers. T_contra = typing.TypeVar('T_contra', contravariant=True) # Ditto contravariant. -if hasattr(typing, 'ClassVar'): - ClassVar = typing.ClassVar -elif hasattr(typing, '_FinalTypingBase'): - class _ClassVar(typing._FinalTypingBase, _root=True): - """Special type construct to mark class variables. - - An annotation wrapped in ClassVar indicates that a given - attribute is intended to be used as a class variable and - should not be set on instances of that class. Usage:: - - class Starship: - stats: ClassVar[Dict[str, int]] = {} # class variable - damage: int = 10 # instance variable - - ClassVar accepts only types and cannot be further subscribed. - - Note that ClassVar is not a class itself, and should not - be used with isinstance() or issubclass(). - """ - - __slots__ = ('__type__',) - - def __init__(self, tp=None, **kwds): - self.__type__ = tp - - def __getitem__(self, item): - cls = type(self) - if self.__type__ is None: - return cls(typing._type_check(item, - '{} accepts only single type.'.format(cls.__name__[1:])), - _root=True) - raise TypeError('{} cannot be further subscripted' - .format(cls.__name__[1:])) - - def _eval_type(self, globalns, localns): - new_tp = typing._eval_type(self.__type__, globalns, localns) - if new_tp == self.__type__: - return self - return type(self)(new_tp, _root=True) - - def __repr__(self): - r = super().__repr__() - if self.__type__ is not None: - r += '[{}]'.format(typing._type_repr(self.__type__)) - return r - - def __hash__(self): - return hash((type(self).__name__, self.__type__)) - - def __eq__(self, other): - if not isinstance(other, _ClassVar): - return NotImplemented - if self.__type__ is not None: - return self.__type__ == other.__type__ - return self is other - - ClassVar = _ClassVar(_root=True) +if sys.version_info >= (3, 11): + from typing import Any else: - class _ClassVarMeta(typing.TypingMeta): - """Metaclass for ClassVar""" - - def __new__(cls, name, bases, namespace, tp=None, _root=False): - self = super().__new__(cls, name, bases, namespace, _root=_root) - if tp is not None: - self.__type__ = tp - return self + class _AnyMeta(type): def __instancecheck__(self, obj): - raise TypeError("ClassVar cannot be used with isinstance().") - - def __subclasscheck__(self, cls): - raise TypeError("ClassVar cannot be used with issubclass().") - - def __getitem__(self, item): - cls = type(self) - if self.__type__ is not None: - raise TypeError('{} cannot be further subscripted' - .format(cls.__name__[1:])) - - param = typing._type_check( - item, - '{} accepts only single type.'.format(cls.__name__[1:])) - return cls(self.__name__, self.__bases__, - dict(self.__dict__), tp=param, _root=True) - - def _eval_type(self, globalns, localns): - new_tp = typing._eval_type(self.__type__, globalns, localns) - if new_tp == self.__type__: - return self - return type(self)(self.__name__, self.__bases__, - dict(self.__dict__), tp=self.__type__, - _root=True) + if self is Any: + raise TypeError("typing_extensions.Any cannot be used with isinstance()") + return super().__instancecheck__(obj) def __repr__(self): - r = super().__repr__() - if self.__type__ is not None: - r += '[{}]'.format(typing._type_repr(self.__type__)) - return r - - def __hash__(self): - return hash((type(self).__name__, self.__type__)) - - def __eq__(self, other): - if not isinstance(other, ClassVar): - return NotImplemented - if self.__type__ is not None: - return self.__type__ == other.__type__ - return self is other - - class ClassVar(typing.Final, metaclass=_ClassVarMeta, _root=True): - """Special type construct to mark class variables. + if self is Any: + return "typing_extensions.Any" + return super().__repr__() + + class Any(metaclass=_AnyMeta): + """Special type indicating an unconstrained type. + - Any is compatible with every type. + - Any assumed to have all methods. + - All values assumed to be instances of Any. + Note that all the above statements are true from the point of view of + static type checkers. At runtime, Any should not be used with instance + checks. + """ + def __new__(cls, *args, **kwargs): + if cls is Any: + raise TypeError("Any cannot be instantiated") + return super().__new__(cls, *args, **kwargs) - An annotation wrapped in ClassVar indicates that a given - attribute is intended to be used as a class variable and - should not be set on instances of that class. Usage:: - class Starship: - stats: ClassVar[Dict[str, int]] = {} # class variable - damage: int = 10 # instance variable +ClassVar = typing.ClassVar - ClassVar accepts only types and cannot be further subscribed. - Note that ClassVar is not a class itself, and should not - be used with isinstance() or issubclass(). - """ +class _ExtensionsSpecialForm(typing._SpecialForm, _root=True): + def __repr__(self): + return 'typing_extensions.' + self._name - __type__ = None # On older versions of typing there is an internal class named "Final". +# 3.8+ if hasattr(typing, 'Final') and sys.version_info[:2] >= (3, 7): Final = typing.Final -elif sys.version_info[:2] >= (3, 7): - class _FinalForm(typing._SpecialForm, _root=True): - - def __repr__(self): - return 'typing_extensions.' + self._name - +# 3.7 +else: + class _FinalForm(_ExtensionsSpecialForm, _root=True): def __getitem__(self, parameters): item = typing._type_check(parameters, - '{} accepts only single type'.format(self._name)) - return _GenericAlias(self, (item,)) + f'{self._name} accepts only a single type.') + return typing._GenericAlias(self, (item,)) Final = _FinalForm('Final', doc="""A special typing construct to indicate that a name @@ -385,134 +274,13 @@ class FastConnector(Connection): TIMEOUT = 1 # Error reported by type checker There is no runtime checking of these properties.""") -elif hasattr(typing, '_FinalTypingBase'): - class _Final(typing._FinalTypingBase, _root=True): - """A special typing construct to indicate that a name - cannot be re-assigned or overridden in a subclass. - For example: - - MAX_SIZE: Final = 9000 - MAX_SIZE += 1 # Error reported by type checker - - class Connection: - TIMEOUT: Final[int] = 10 - class FastConnector(Connection): - TIMEOUT = 1 # Error reported by type checker - - There is no runtime checking of these properties. - """ - - __slots__ = ('__type__',) - - def __init__(self, tp=None, **kwds): - self.__type__ = tp - - def __getitem__(self, item): - cls = type(self) - if self.__type__ is None: - return cls(typing._type_check(item, - '{} accepts only single type.'.format(cls.__name__[1:])), - _root=True) - raise TypeError('{} cannot be further subscripted' - .format(cls.__name__[1:])) - - def _eval_type(self, globalns, localns): - new_tp = typing._eval_type(self.__type__, globalns, localns) - if new_tp == self.__type__: - return self - return type(self)(new_tp, _root=True) - - def __repr__(self): - r = super().__repr__() - if self.__type__ is not None: - r += '[{}]'.format(typing._type_repr(self.__type__)) - return r - - def __hash__(self): - return hash((type(self).__name__, self.__type__)) - - def __eq__(self, other): - if not isinstance(other, _Final): - return NotImplemented - if self.__type__ is not None: - return self.__type__ == other.__type__ - return self is other - - Final = _Final(_root=True) -else: - class _FinalMeta(typing.TypingMeta): - """Metaclass for Final""" - - def __new__(cls, name, bases, namespace, tp=None, _root=False): - self = super().__new__(cls, name, bases, namespace, _root=_root) - if tp is not None: - self.__type__ = tp - return self - def __instancecheck__(self, obj): - raise TypeError("Final cannot be used with isinstance().") - - def __subclasscheck__(self, cls): - raise TypeError("Final cannot be used with issubclass().") - - def __getitem__(self, item): - cls = type(self) - if self.__type__ is not None: - raise TypeError('{} cannot be further subscripted' - .format(cls.__name__[1:])) - - param = typing._type_check( - item, - '{} accepts only single type.'.format(cls.__name__[1:])) - return cls(self.__name__, self.__bases__, - dict(self.__dict__), tp=param, _root=True) - - def _eval_type(self, globalns, localns): - new_tp = typing._eval_type(self.__type__, globalns, localns) - if new_tp == self.__type__: - return self - return type(self)(self.__name__, self.__bases__, - dict(self.__dict__), tp=self.__type__, - _root=True) - - def __repr__(self): - r = super().__repr__() - if self.__type__ is not None: - r += '[{}]'.format(typing._type_repr(self.__type__)) - return r - - def __hash__(self): - return hash((type(self).__name__, self.__type__)) - - def __eq__(self, other): - if not isinstance(other, Final): - return NotImplemented - if self.__type__ is not None: - return self.__type__ == other.__type__ - return self is other - - class Final(typing.Final, metaclass=_FinalMeta, _root=True): - """A special typing construct to indicate that a name - cannot be re-assigned or overridden in a subclass. - For example: - - MAX_SIZE: Final = 9000 - MAX_SIZE += 1 # Error reported by type checker - - class Connection: - TIMEOUT: Final[int] = 10 - class FastConnector(Connection): - TIMEOUT = 1 # Error reported by type checker - - There is no runtime checking of these properties. - """ - - __type__ = None - - -if hasattr(typing, 'final'): +if sys.version_info >= (3, 11): final = typing.final else: + # @final exists in 3.8+, but we backport it for all versions + # before 3.11 to keep support for the __final__ attribute. + # See https://bugs.python.org/issue46342 def final(f): """This decorator can be used to indicate to type checkers that the decorated method cannot be overridden, and decorated class @@ -531,28 +299,85 @@ class Leaf: class Other(Leaf): # Error reported by type checker ... - There is no runtime checking of these properties. + There is no runtime checking of these properties. The decorator + sets the ``__final__`` attribute to ``True`` on the decorated object + to allow runtime introspection. """ + try: + f.__final__ = True + except (AttributeError, TypeError): + # Skip the attribute silently if it is not writable. + # AttributeError happens if the object has __slots__ or a + # read-only property, TypeError if it's a builtin class. + pass return f def IntVar(name): - return TypeVar(name) + return typing.TypeVar(name) -if hasattr(typing, 'Literal'): +# A Literal bug was fixed in 3.11.0, 3.10.1 and 3.9.8 +if sys.version_info >= (3, 10, 1): Literal = typing.Literal -elif sys.version_info[:2] >= (3, 7): - class _LiteralForm(typing._SpecialForm, _root=True): +else: + def _flatten_literal_params(parameters): + """An internal helper for Literal creation: flatten Literals among parameters""" + params = [] + for p in parameters: + if isinstance(p, _LiteralGenericAlias): + params.extend(p.__args__) + else: + params.append(p) + return tuple(params) - def __repr__(self): - return 'typing_extensions.' + self._name + def _value_and_type_iter(params): + for p in params: + yield p, type(p) + + class _LiteralGenericAlias(typing._GenericAlias, _root=True): + def __eq__(self, other): + if not isinstance(other, _LiteralGenericAlias): + return NotImplemented + these_args_deduped = set(_value_and_type_iter(self.__args__)) + other_args_deduped = set(_value_and_type_iter(other.__args__)) + return these_args_deduped == other_args_deduped + + def __hash__(self): + return hash(frozenset(_value_and_type_iter(self.__args__))) + + class _LiteralForm(_ExtensionsSpecialForm, _root=True): + def __init__(self, doc: str): + self._name = 'Literal' + self._doc = self.__doc__ = doc def __getitem__(self, parameters): - return _GenericAlias(self, parameters) + if not isinstance(parameters, tuple): + parameters = (parameters,) - Literal = _LiteralForm('Literal', - doc="""A type that can be used to indicate to type checkers + parameters = _flatten_literal_params(parameters) + + val_type_pairs = list(_value_and_type_iter(parameters)) + try: + deduped_pairs = set(val_type_pairs) + except TypeError: + # unhashable parameters + pass + else: + # similar logic to typing._deduplicate on Python 3.9+ + if len(deduped_pairs) < len(val_type_pairs): + new_parameters = [] + for pair in val_type_pairs: + if pair in deduped_pairs: + new_parameters.append(pair[0]) + deduped_pairs.remove(pair) + assert not deduped_pairs, deduped_pairs + parameters = tuple(new_parameters) + + return _LiteralGenericAlias(self, parameters) + + Literal = _LiteralForm(doc="""\ + A type that can be used to indicate to type checkers that the corresponding value has a value literally equivalent to the provided parameter. For example: @@ -564,1605 +389,2684 @@ def __getitem__(self, parameters): Literal[...] cannot be subclassed. There is no runtime checking verifying that the parameter is actually a value instead of a type.""") -elif hasattr(typing, '_FinalTypingBase'): - class _Literal(typing._FinalTypingBase, _root=True): - """A type that can be used to indicate to type checkers that the - corresponding value has a value literally equivalent to the - provided parameter. For example: - var: Literal[4] = 4 - The type checker understands that 'var' is literally equal to the - value 4 and no other value. +_overload_dummy = typing._overload_dummy - Literal[...] cannot be subclassed. There is no runtime checking - verifying that the parameter is actually a value instead of a type. + +if hasattr(typing, "get_overloads"): # 3.11+ + overload = typing.overload + get_overloads = typing.get_overloads + clear_overloads = typing.clear_overloads +else: + # {module: {qualname: {firstlineno: func}}} + _overload_registry = collections.defaultdict( + functools.partial(collections.defaultdict, dict) + ) + + def overload(func): + """Decorator for overloaded functions/methods. + + In a stub file, place two or more stub definitions for the same + function in a row, each decorated with @overload. For example: + + @overload + def utf8(value: None) -> None: ... + @overload + def utf8(value: bytes) -> bytes: ... + @overload + def utf8(value: str) -> bytes: ... + + In a non-stub file (i.e. a regular .py file), do the same but + follow it with an implementation. The implementation should *not* + be decorated with @overload. For example: + + @overload + def utf8(value: None) -> None: ... + @overload + def utf8(value: bytes) -> bytes: ... + @overload + def utf8(value: str) -> bytes: ... + def utf8(value): + # implementation goes here + + The overloads for a function can be retrieved at runtime using the + get_overloads() function. """ + # classmethod and staticmethod + f = getattr(func, "__func__", func) + try: + _overload_registry[f.__module__][f.__qualname__][ + f.__code__.co_firstlineno + ] = func + except AttributeError: + # Not a normal function; ignore. + pass + return _overload_dummy - __slots__ = ('__values__',) + def get_overloads(func): + """Return all defined overloads for *func* as a sequence.""" + # classmethod and staticmethod + f = getattr(func, "__func__", func) + if f.__module__ not in _overload_registry: + return [] + mod_dict = _overload_registry[f.__module__] + if f.__qualname__ not in mod_dict: + return [] + return list(mod_dict[f.__qualname__].values()) - def __init__(self, values=None, **kwds): - self.__values__ = values + def clear_overloads(): + """Clear all overloads in the registry.""" + _overload_registry.clear() - def __getitem__(self, values): - cls = type(self) - if self.__values__ is None: - if not isinstance(values, tuple): - values = (values,) - return cls(values, _root=True) - raise TypeError('{} cannot be further subscripted' - .format(cls.__name__[1:])) - def _eval_type(self, globalns, localns): - return self +# This is not a real generic class. Don't use outside annotations. +Type = typing.Type - def __repr__(self): - r = super().__repr__() - if self.__values__ is not None: - r += '[{}]'.format(', '.join(map(typing._type_repr, self.__values__))) - return r +# Various ABCs mimicking those in collections.abc. +# A few are simply re-exported for completeness. - def __hash__(self): - return hash((type(self).__name__, self.__values__)) - def __eq__(self, other): - if not isinstance(other, _Literal): - return NotImplemented - if self.__values__ is not None: - return self.__values__ == other.__values__ - return self is other +Awaitable = typing.Awaitable +Coroutine = typing.Coroutine +AsyncIterable = typing.AsyncIterable +AsyncIterator = typing.AsyncIterator +Deque = typing.Deque +ContextManager = typing.ContextManager +AsyncContextManager = typing.AsyncContextManager +DefaultDict = typing.DefaultDict - Literal = _Literal(_root=True) +# 3.7.2+ +if hasattr(typing, 'OrderedDict'): + OrderedDict = typing.OrderedDict +# 3.7.0-3.7.2 else: - class _LiteralMeta(typing.TypingMeta): - """Metaclass for Literal""" + OrderedDict = typing._alias(collections.OrderedDict, (KT, VT)) - def __new__(cls, name, bases, namespace, values=None, _root=False): - self = super().__new__(cls, name, bases, namespace, _root=_root) - if values is not None: - self.__values__ = values - return self +Counter = typing.Counter +ChainMap = typing.ChainMap +AsyncGenerator = typing.AsyncGenerator +Text = typing.Text +TYPE_CHECKING = typing.TYPE_CHECKING - def __instancecheck__(self, obj): - raise TypeError("Literal cannot be used with isinstance().") - def __subclasscheck__(self, cls): - raise TypeError("Literal cannot be used with issubclass().") +_PROTO_ALLOWLIST = { + 'collections.abc': [ + 'Callable', 'Awaitable', 'Iterable', 'Iterator', 'AsyncIterable', + 'Hashable', 'Sized', 'Container', 'Collection', 'Reversible', 'Buffer', + ], + 'contextlib': ['AbstractContextManager', 'AbstractAsyncContextManager'], + 'typing_extensions': ['Buffer'], +} - def __getitem__(self, item): - cls = type(self) - if self.__values__ is not None: - raise TypeError('{} cannot be further subscripted' - .format(cls.__name__[1:])) - if not isinstance(item, tuple): - item = (item,) - return cls(self.__name__, self.__bases__, - dict(self.__dict__), values=item, _root=True) +_EXCLUDED_ATTRS = { + "__abstractmethods__", "__annotations__", "__weakref__", "_is_protocol", + "_is_runtime_protocol", "__dict__", "__slots__", "__parameters__", + "__orig_bases__", "__module__", "_MutableMapping__marker", "__doc__", + "__subclasshook__", "__orig_class__", "__init__", "__new__", + "__protocol_attrs__", "__callable_proto_members_only__", +} - def _eval_type(self, globalns, localns): - return self +if sys.version_info < (3, 8): + _EXCLUDED_ATTRS |= { + "_gorg", "__next_in_mro__", "__extra__", "__tree_hash__", "__args__", + "__origin__" + } - def __repr__(self): - r = super().__repr__() - if self.__values__ is not None: - r += '[{}]'.format(', '.join(map(typing._type_repr, self.__values__))) - return r +if sys.version_info >= (3, 9): + _EXCLUDED_ATTRS.add("__class_getitem__") - def __hash__(self): - return hash((type(self).__name__, self.__values__)) +if sys.version_info >= (3, 12): + _EXCLUDED_ATTRS.add("__type_params__") - def __eq__(self, other): - if not isinstance(other, Literal): - return NotImplemented - if self.__values__ is not None: - return self.__values__ == other.__values__ - return self is other +_EXCLUDED_ATTRS = frozenset(_EXCLUDED_ATTRS) - class Literal(typing.Final, metaclass=_LiteralMeta, _root=True): - """A type that can be used to indicate to type checkers that the - corresponding value has a value literally equivalent to the - provided parameter. For example: - var: Literal[4] = 4 +def _get_protocol_attrs(cls): + attrs = set() + for base in cls.__mro__[:-1]: # without object + if base.__name__ in {'Protocol', 'Generic'}: + continue + annotations = getattr(base, '__annotations__', {}) + for attr in (*base.__dict__, *annotations): + if (not attr.startswith('_abc_') and attr not in _EXCLUDED_ATTRS): + attrs.add(attr) + return attrs - The type checker understands that 'var' is literally equal to the - value 4 and no other value. - Literal[...] cannot be subclassed. There is no runtime checking - verifying that the parameter is actually a value instead of a type. - """ +def _maybe_adjust_parameters(cls): + """Helper function used in Protocol.__init_subclass__ and _TypedDictMeta.__new__. - __values__ = None + The contents of this function are very similar + to logic found in typing.Generic.__init_subclass__ + on the CPython main branch. + """ + tvars = [] + if '__orig_bases__' in cls.__dict__: + tvars = _collect_type_vars(cls.__orig_bases__) + # Look for Generic[T1, ..., Tn] or Protocol[T1, ..., Tn]. + # If found, tvars must be a subset of it. + # If not found, tvars is it. + # Also check for and reject plain Generic, + # and reject multiple Generic[...] and/or Protocol[...]. + gvars = None + for base in cls.__orig_bases__: + if (isinstance(base, typing._GenericAlias) and + base.__origin__ in (typing.Generic, Protocol)): + # for error messages + the_base = base.__origin__.__name__ + if gvars is not None: + raise TypeError( + "Cannot inherit from Generic[...]" + " and/or Protocol[...] multiple types.") + gvars = base.__parameters__ + if gvars is None: + gvars = tvars + else: + tvarset = set(tvars) + gvarset = set(gvars) + if not tvarset <= gvarset: + s_vars = ', '.join(str(t) for t in tvars if t not in gvarset) + s_args = ', '.join(str(g) for g in gvars) + raise TypeError(f"Some type variables ({s_vars}) are" + f" not listed in {the_base}[{s_args}]") + tvars = gvars + cls.__parameters__ = tuple(tvars) + + +def _caller(depth=2): + try: + return sys._getframe(depth).f_globals.get('__name__', '__main__') + except (AttributeError, ValueError): # For platforms without _getframe() + return None -def _overload_dummy(*args, **kwds): - """Helper for @overload to raise when called.""" - raise NotImplementedError( - "You should not call an overloaded function. " - "A series of @overload-decorated functions " - "outside a stub module should always be followed " - "by an implementation that is not @overload-ed.") +# The performance of runtime-checkable protocols is significantly improved on Python 3.12, +# so we backport the 3.12 version of Protocol to Python <=3.11 +if sys.version_info >= (3, 12): + Protocol = typing.Protocol +else: + def _allow_reckless_class_checks(depth=3): + """Allow instance and class checks for special stdlib modules. + The abc and functools modules indiscriminately call isinstance() and + issubclass() on the whole MRO of a user class, which may contain protocols. + """ + return _caller(depth) in {'abc', 'functools', None} + + def _no_init(self, *args, **kwargs): + if type(self)._is_protocol: + raise TypeError('Protocols cannot be instantiated') + + if sys.version_info >= (3, 8): + # Inheriting from typing._ProtocolMeta isn't actually desirable, + # but is necessary to allow typing.Protocol and typing_extensions.Protocol + # to mix without getting TypeErrors about "metaclass conflict" + _typing_Protocol = typing.Protocol + _ProtocolMetaBase = type(_typing_Protocol) + else: + _typing_Protocol = _marker + _ProtocolMetaBase = abc.ABCMeta + + class _ProtocolMeta(_ProtocolMetaBase): + # This metaclass is somewhat unfortunate, + # but is necessary for several reasons... + # + # NOTE: DO NOT call super() in any methods in this class + # That would call the methods on typing._ProtocolMeta on Python 3.8-3.11 + # and those are slow + def __new__(mcls, name, bases, namespace, **kwargs): + if name == "Protocol" and len(bases) < 2: + pass + elif {Protocol, _typing_Protocol} & set(bases): + for base in bases: + if not ( + base in {object, typing.Generic, Protocol, _typing_Protocol} + or base.__name__ in _PROTO_ALLOWLIST.get(base.__module__, []) + or is_protocol(base) + ): + raise TypeError( + f"Protocols can only inherit from other protocols, " + f"got {base!r}" + ) + return abc.ABCMeta.__new__(mcls, name, bases, namespace, **kwargs) + def __init__(cls, *args, **kwargs): + abc.ABCMeta.__init__(cls, *args, **kwargs) + if getattr(cls, "_is_protocol", False): + cls.__protocol_attrs__ = _get_protocol_attrs(cls) + # PEP 544 prohibits using issubclass() + # with protocols that have non-method members. + cls.__callable_proto_members_only__ = all( + callable(getattr(cls, attr, None)) for attr in cls.__protocol_attrs__ + ) + + def __subclasscheck__(cls, other): + if cls is Protocol: + return type.__subclasscheck__(cls, other) + if ( + getattr(cls, '_is_protocol', False) + and not _allow_reckless_class_checks() + ): + if not isinstance(other, type): + # Same error message as for issubclass(1, int). + raise TypeError('issubclass() arg 1 must be a class') + if ( + not cls.__callable_proto_members_only__ + and cls.__dict__.get("__subclasshook__") is _proto_hook + ): + raise TypeError( + "Protocols with non-method members don't support issubclass()" + ) + if not getattr(cls, '_is_runtime_protocol', False): + raise TypeError( + "Instance and class checks can only be used with " + "@runtime_checkable protocols" + ) + return abc.ABCMeta.__subclasscheck__(cls, other) -def overload(func): - """Decorator for overloaded functions/methods. + def __instancecheck__(cls, instance): + # We need this method for situations where attributes are + # assigned in __init__. + if cls is Protocol: + return type.__instancecheck__(cls, instance) + if not getattr(cls, "_is_protocol", False): + # i.e., it's a concrete subclass of a protocol + return abc.ABCMeta.__instancecheck__(cls, instance) + + if ( + not getattr(cls, '_is_runtime_protocol', False) and + not _allow_reckless_class_checks() + ): + raise TypeError("Instance and class checks can only be used with" + " @runtime_checkable protocols") - In a stub file, place two or more stub definitions for the same - function in a row, each decorated with @overload. For example: + if abc.ABCMeta.__instancecheck__(cls, instance): + return True - @overload - def utf8(value: None) -> None: ... - @overload - def utf8(value: bytes) -> bytes: ... - @overload - def utf8(value: str) -> bytes: ... + for attr in cls.__protocol_attrs__: + try: + val = inspect.getattr_static(instance, attr) + except AttributeError: + break + if val is None and callable(getattr(cls, attr, None)): + break + else: + return True - In a non-stub file (i.e. a regular .py file), do the same but - follow it with an implementation. The implementation should *not* - be decorated with @overload. For example: + return False - @overload - def utf8(value: None) -> None: ... - @overload - def utf8(value: bytes) -> bytes: ... - @overload - def utf8(value: str) -> bytes: ... - def utf8(value): - # implementation goes here - """ - return _overload_dummy + def __eq__(cls, other): + # Hack so that typing.Generic.__class_getitem__ + # treats typing_extensions.Protocol + # as equivalent to typing.Protocol on Python 3.8+ + if abc.ABCMeta.__eq__(cls, other) is True: + return True + return ( + cls is Protocol and other is getattr(typing, "Protocol", object()) + ) + # This has to be defined, or the abc-module cache + # complains about classes with this metaclass being unhashable, + # if we define only __eq__! + def __hash__(cls) -> int: + return type.__hash__(cls) -# This is not a real generic class. Don't use outside annotations. -if hasattr(typing, 'Type'): - Type = typing.Type -else: - # Internal type variable used for Type[]. - CT_co = typing.TypeVar('CT_co', covariant=True, bound=type) + @classmethod + def _proto_hook(cls, other): + if not cls.__dict__.get('_is_protocol', False): + return NotImplemented - class Type(typing.Generic[CT_co], extra=type): - """A special construct usable to annotate class objects. + for attr in cls.__protocol_attrs__: + for base in other.__mro__: + # Check if the members appears in the class dictionary... + if attr in base.__dict__: + if base.__dict__[attr] is None: + return NotImplemented + break - For example, suppose we have the following classes:: + # ...or in annotations, if it is a sub-protocol. + annotations = getattr(base, '__annotations__', {}) + if ( + isinstance(annotations, collections.abc.Mapping) + and attr in annotations + and is_protocol(other) + ): + break + else: + return NotImplemented + return True - class User: ... # Abstract base for User classes - class BasicUser(User): ... - class ProUser(User): ... - class TeamUser(User): ... + if sys.version_info >= (3, 8): + class Protocol(typing.Generic, metaclass=_ProtocolMeta): + __doc__ = typing.Protocol.__doc__ + __slots__ = () + _is_protocol = True + _is_runtime_protocol = False - And a function that takes a class argument that's a subclass of - User and returns an instance of the corresponding class:: + def __init_subclass__(cls, *args, **kwargs): + super().__init_subclass__(*args, **kwargs) - U = TypeVar('U', bound=User) - def new_user(user_class: Type[U]) -> U: - user = user_class() - # (Here we could write the user object to a database) - return user - joe = new_user(BasicUser) + # Determine if this is a protocol or a concrete subclass. + if not cls.__dict__.get('_is_protocol', False): + cls._is_protocol = any(b is Protocol for b in cls.__bases__) - At this point the type checker knows that joe has type BasicUser. - """ + # Set (or override) the protocol subclass hook. + if '__subclasshook__' not in cls.__dict__: + cls.__subclasshook__ = _proto_hook - __slots__ = () + # Prohibit instantiation for protocol classes + if cls._is_protocol and cls.__init__ is Protocol.__init__: + cls.__init__ = _no_init + else: + class Protocol(metaclass=_ProtocolMeta): + # There is quite a lot of overlapping code with typing.Generic. + # Unfortunately it is hard to avoid this on Python <3.8, + # as the typing module on Python 3.7 doesn't let us subclass typing.Generic! + """Base class for protocol classes. Protocol classes are defined as:: -# Various ABCs mimicking those in collections.abc. -# A few are simply re-exported for completeness. + class Proto(Protocol): + def meth(self) -> int: + ... -def _define_guard(type_name): - """ - Returns True if the given type isn't defined in typing but - is defined in collections_abc. + Such classes are primarily used with static type checkers that recognize + structural subtyping (static duck-typing), for example:: - Adds the type to __all__ if the collection is found in either - typing or collection_abc. - """ - if hasattr(typing, type_name): - __all__.append(type_name) - globals()[type_name] = getattr(typing, type_name) - return False - elif hasattr(collections_abc, type_name): - __all__.append(type_name) - return True - else: - return False + class C: + def meth(self) -> int: + return 0 + def func(x: Proto) -> int: + return x.meth() -class _ExtensionsGenericMeta(GenericMeta): - def __subclasscheck__(self, subclass): - """This mimics a more modern GenericMeta.__subclasscheck__() logic - (that does not have problems with recursion) to work around interactions - between collections, typing, and typing_extensions on older - versions of Python, see https://github.com/python/typing/issues/501. - """ - if sys.version_info[:3] >= (3, 5, 3) or sys.version_info[:3] < (3, 5, 0): - if self.__origin__ is not None: - if sys._getframe(1).f_globals['__name__'] not in ['abc', 'functools']: - raise TypeError("Parameterized generics cannot be used with class " - "or instance checks") - return False - if not self.__extra__: - return super().__subclasscheck__(subclass) - res = self.__extra__.__subclasshook__(subclass) - if res is not NotImplemented: - return res - if self.__extra__ in subclass.__mro__: - return True - for scls in self.__extra__.__subclasses__(): - if isinstance(scls, GenericMeta): - continue - if issubclass(subclass, scls): - return True - return False + func(C()) # Passes static type check + See PEP 544 for details. Protocol classes decorated with + @typing_extensions.runtime_checkable act + as simple-minded runtime-checkable protocols that check + only the presence of given attributes, ignoring their type signatures. -if _define_guard('Awaitable'): - class Awaitable(typing.Generic[T_co], metaclass=_ExtensionsGenericMeta, - extra=collections_abc.Awaitable): - __slots__ = () + Protocol classes can be generic, they are defined as:: + class GenProto(Protocol[T]): + def meth(self) -> T: + ... + """ + __slots__ = () + _is_protocol = True + _is_runtime_protocol = False -if _define_guard('Coroutine'): - class Coroutine(Awaitable[V_co], typing.Generic[T_co, T_contra, V_co], - metaclass=_ExtensionsGenericMeta, - extra=collections_abc.Coroutine): - __slots__ = () + def __new__(cls, *args, **kwds): + if cls is Protocol: + raise TypeError("Type Protocol cannot be instantiated; " + "it can only be used as a base class") + return super().__new__(cls) + @typing._tp_cache + def __class_getitem__(cls, params): + if not isinstance(params, tuple): + params = (params,) + if not params and cls is not typing.Tuple: + raise TypeError( + f"Parameter list to {cls.__qualname__}[...] cannot be empty") + msg = "Parameters to generic types must be types." + params = tuple(typing._type_check(p, msg) for p in params) + if cls is Protocol: + # Generic can only be subscripted with unique type variables. + if not all(isinstance(p, typing.TypeVar) for p in params): + i = 0 + while isinstance(params[i], typing.TypeVar): + i += 1 + raise TypeError( + "Parameters to Protocol[...] must all be type variables." + f" Parameter {i + 1} is {params[i]}") + if len(set(params)) != len(params): + raise TypeError( + "Parameters to Protocol[...] must all be unique") + else: + # Subscripting a regular Generic subclass. + _check_generic(cls, params, len(cls.__parameters__)) + return typing._GenericAlias(cls, params) -if _define_guard('AsyncIterable'): - class AsyncIterable(typing.Generic[T_co], - metaclass=_ExtensionsGenericMeta, - extra=collections_abc.AsyncIterable): - __slots__ = () + def __init_subclass__(cls, *args, **kwargs): + if '__orig_bases__' in cls.__dict__: + error = typing.Generic in cls.__orig_bases__ + else: + error = typing.Generic in cls.__bases__ + if error: + raise TypeError("Cannot inherit from plain Generic") + _maybe_adjust_parameters(cls) + # Determine if this is a protocol or a concrete subclass. + if not cls.__dict__.get('_is_protocol', None): + cls._is_protocol = any(b is Protocol for b in cls.__bases__) -if _define_guard('AsyncIterator'): - class AsyncIterator(AsyncIterable[T_co], - metaclass=_ExtensionsGenericMeta, - extra=collections_abc.AsyncIterator): - __slots__ = () + # Set (or override) the protocol subclass hook. + if '__subclasshook__' not in cls.__dict__: + cls.__subclasshook__ = _proto_hook + # Prohibit instantiation for protocol classes + if cls._is_protocol and cls.__init__ is Protocol.__init__: + cls.__init__ = _no_init -if hasattr(typing, 'Deque'): - Deque = typing.Deque -elif _geqv_defined: - class Deque(collections.deque, typing.MutableSequence[T], - metaclass=_ExtensionsGenericMeta, - extra=collections.deque): - __slots__ = () - def __new__(cls, *args, **kwds): - if _geqv(cls, Deque): - return collections.deque(*args, **kwds) - return _generic_new(collections.deque, cls, *args, **kwds) +if sys.version_info >= (3, 8): + runtime_checkable = typing.runtime_checkable else: - class Deque(collections.deque, typing.MutableSequence[T], - metaclass=_ExtensionsGenericMeta, - extra=collections.deque): - __slots__ = () + def runtime_checkable(cls): + """Mark a protocol class as a runtime protocol, so that it + can be used with isinstance() and issubclass(). Raise TypeError + if applied to a non-protocol class. + + This allows a simple-minded structural check very similar to the + one-offs in collections.abc such as Hashable. + """ + if not ( + (isinstance(cls, _ProtocolMeta) or issubclass(cls, typing.Generic)) + and getattr(cls, "_is_protocol", False) + ): + raise TypeError('@runtime_checkable can be only applied to protocol classes,' + f' got {cls!r}') + cls._is_runtime_protocol = True + return cls - def __new__(cls, *args, **kwds): - if cls._gorg is Deque: - return collections.deque(*args, **kwds) - return _generic_new(collections.deque, cls, *args, **kwds) +# Exists for backwards compatibility. +runtime = runtime_checkable -if hasattr(typing, 'ContextManager'): - ContextManager = typing.ContextManager -elif hasattr(contextlib, 'AbstractContextManager'): - class ContextManager(typing.Generic[T_co], - metaclass=_ExtensionsGenericMeta, - extra=contextlib.AbstractContextManager): - __slots__ = () + +# Our version of runtime-checkable protocols is faster on Python 3.7-3.11 +if sys.version_info >= (3, 12): + SupportsInt = typing.SupportsInt + SupportsFloat = typing.SupportsFloat + SupportsComplex = typing.SupportsComplex + SupportsBytes = typing.SupportsBytes + SupportsIndex = typing.SupportsIndex + SupportsAbs = typing.SupportsAbs + SupportsRound = typing.SupportsRound else: - class ContextManager(typing.Generic[T_co]): + @runtime_checkable + class SupportsInt(Protocol): + """An ABC with one abstract method __int__.""" __slots__ = () - def __enter__(self): - return self - @abc.abstractmethod - def __exit__(self, exc_type, exc_value, traceback): - return None - - @classmethod - def __subclasshook__(cls, C): - if cls is ContextManager: - # In Python 3.6+, it is possible to set a method to None to - # explicitly indicate that the class does not implement an ABC - # (https://bugs.python.org/issue25958), but we do not support - # that pattern here because this fallback class is only used - # in Python 3.5 and earlier. - if (any("__enter__" in B.__dict__ for B in C.__mro__) and - any("__exit__" in B.__dict__ for B in C.__mro__)): - return True - return NotImplemented - + def __int__(self) -> int: + pass -if hasattr(typing, 'AsyncContextManager'): - AsyncContextManager = typing.AsyncContextManager - __all__.append('AsyncContextManager') -elif hasattr(contextlib, 'AbstractAsyncContextManager'): - class AsyncContextManager(typing.Generic[T_co], - metaclass=_ExtensionsGenericMeta, - extra=contextlib.AbstractAsyncContextManager): + @runtime_checkable + class SupportsFloat(Protocol): + """An ABC with one abstract method __float__.""" __slots__ = () - __all__.append('AsyncContextManager') -elif sys.version_info[:2] >= (3, 5): - exec(""" -class AsyncContextManager(typing.Generic[T_co]): - __slots__ = () + @abc.abstractmethod + def __float__(self) -> float: + pass - async def __aenter__(self): - return self + @runtime_checkable + class SupportsComplex(Protocol): + """An ABC with one abstract method __complex__.""" + __slots__ = () - @abc.abstractmethod - async def __aexit__(self, exc_type, exc_value, traceback): + @abc.abstractmethod + def __complex__(self) -> complex: + pass + + @runtime_checkable + class SupportsBytes(Protocol): + """An ABC with one abstract method __bytes__.""" + __slots__ = () + + @abc.abstractmethod + def __bytes__(self) -> bytes: + pass + + @runtime_checkable + class SupportsIndex(Protocol): + __slots__ = () + + @abc.abstractmethod + def __index__(self) -> int: + pass + + @runtime_checkable + class SupportsAbs(Protocol[T_co]): + """ + An ABC with one abstract method __abs__ that is covariant in its return type. + """ + __slots__ = () + + @abc.abstractmethod + def __abs__(self) -> T_co: + pass + + @runtime_checkable + class SupportsRound(Protocol[T_co]): + """ + An ABC with one abstract method __round__ that is covariant in its return type. + """ + __slots__ = () + + @abc.abstractmethod + def __round__(self, ndigits: int = 0) -> T_co: + pass + + +def _ensure_subclassable(mro_entries): + def inner(func): + if sys.implementation.name == "pypy" and sys.version_info < (3, 9): + cls_dict = { + "__call__": staticmethod(func), + "__mro_entries__": staticmethod(mro_entries) + } + t = type(func.__name__, (), cls_dict) + return functools.update_wrapper(t(), func) + else: + func.__mro_entries__ = mro_entries + return func + return inner + + +if sys.version_info >= (3, 13): + # The standard library TypedDict in Python 3.8 does not store runtime information + # about which (if any) keys are optional. See https://bugs.python.org/issue38834 + # The standard library TypedDict in Python 3.9.0/1 does not honour the "total" + # keyword with old-style TypedDict(). See https://bugs.python.org/issue42059 + # The standard library TypedDict below Python 3.11 does not store runtime + # information about optional and required keys when using Required or NotRequired. + # Generic TypedDicts are also impossible using typing.TypedDict on Python <3.11. + # Aaaand on 3.12 we add __orig_bases__ to TypedDict + # to enable better runtime introspection. + # On 3.13 we deprecate some odd ways of creating TypedDicts. + TypedDict = typing.TypedDict + _TypedDictMeta = typing._TypedDictMeta + is_typeddict = typing.is_typeddict +else: + # 3.10.0 and later + _TAKES_MODULE = "module" in inspect.signature(typing._type_check).parameters + + if sys.version_info >= (3, 8): + _fake_name = "Protocol" + else: + _fake_name = "_Protocol" + + class _TypedDictMeta(type): + def __new__(cls, name, bases, ns, total=True): + """Create new typed dict class object. + + This method is called when TypedDict is subclassed, + or when TypedDict is instantiated. This way + TypedDict supports all three syntax forms described in its docstring. + Subclasses and instances of TypedDict return actual dictionaries. + """ + for base in bases: + if type(base) is not _TypedDictMeta and base is not typing.Generic: + raise TypeError('cannot inherit from both a TypedDict type ' + 'and a non-TypedDict base class') + + if any(issubclass(b, typing.Generic) for b in bases): + generic_base = (typing.Generic,) + else: + generic_base = () + + # typing.py generally doesn't let you inherit from plain Generic, unless + # the name of the class happens to be "Protocol" (or "_Protocol" on 3.7). + tp_dict = type.__new__(_TypedDictMeta, _fake_name, (*generic_base, dict), ns) + tp_dict.__name__ = name + if tp_dict.__qualname__ == _fake_name: + tp_dict.__qualname__ = name + + if not hasattr(tp_dict, '__orig_bases__'): + tp_dict.__orig_bases__ = bases + + annotations = {} + own_annotations = ns.get('__annotations__', {}) + msg = "TypedDict('Name', {f0: t0, f1: t1, ...}); each t must be a type" + if _TAKES_MODULE: + own_annotations = { + n: typing._type_check(tp, msg, module=tp_dict.__module__) + for n, tp in own_annotations.items() + } + else: + own_annotations = { + n: typing._type_check(tp, msg) + for n, tp in own_annotations.items() + } + required_keys = set() + optional_keys = set() + + for base in bases: + annotations.update(base.__dict__.get('__annotations__', {})) + required_keys.update(base.__dict__.get('__required_keys__', ())) + optional_keys.update(base.__dict__.get('__optional_keys__', ())) + + annotations.update(own_annotations) + for annotation_key, annotation_type in own_annotations.items(): + annotation_origin = get_origin(annotation_type) + if annotation_origin is Annotated: + annotation_args = get_args(annotation_type) + if annotation_args: + annotation_type = annotation_args[0] + annotation_origin = get_origin(annotation_type) + + if annotation_origin is Required: + required_keys.add(annotation_key) + elif annotation_origin is NotRequired: + optional_keys.add(annotation_key) + elif total: + required_keys.add(annotation_key) + else: + optional_keys.add(annotation_key) + + tp_dict.__annotations__ = annotations + tp_dict.__required_keys__ = frozenset(required_keys) + tp_dict.__optional_keys__ = frozenset(optional_keys) + if not hasattr(tp_dict, '__total__'): + tp_dict.__total__ = total + return tp_dict + + __call__ = dict # static method + + def __subclasscheck__(cls, other): + # Typed dicts are only for static structural subtyping. + raise TypeError('TypedDict does not support instance and class checks') + + __instancecheck__ = __subclasscheck__ + + _TypedDict = type.__new__(_TypedDictMeta, 'TypedDict', (), {}) + + @_ensure_subclassable(lambda bases: (_TypedDict,)) + def TypedDict(__typename, __fields=_marker, *, total=True, **kwargs): + """A simple typed namespace. At runtime it is equivalent to a plain dict. + + TypedDict creates a dictionary type such that a type checker will expect all + instances to have a certain set of keys, where each key is + associated with a value of a consistent type. This expectation + is not checked at runtime. + + Usage:: + + class Point2D(TypedDict): + x: int + y: int + label: str + + a: Point2D = {'x': 1, 'y': 2, 'label': 'good'} # OK + b: Point2D = {'z': 3, 'label': 'bad'} # Fails type check + + assert Point2D(x=1, y=2, label='first') == dict(x=1, y=2, label='first') + + The type info can be accessed via the Point2D.__annotations__ dict, and + the Point2D.__required_keys__ and Point2D.__optional_keys__ frozensets. + TypedDict supports an additional equivalent form:: + + Point2D = TypedDict('Point2D', {'x': int, 'y': int, 'label': str}) + + By default, all keys must be present in a TypedDict. It is possible + to override this by specifying totality:: + + class Point2D(TypedDict, total=False): + x: int + y: int + + This means that a Point2D TypedDict can have any of the keys omitted. A type + checker is only expected to support a literal False or True as the value of + the total argument. True is the default, and makes all items defined in the + class body be required. + + The Required and NotRequired special forms can also be used to mark + individual keys as being required or not required:: + + class Point2D(TypedDict): + x: int # the "x" key must always be present (Required is the default) + y: NotRequired[int] # the "y" key can be omitted + + See PEP 655 for more details on Required and NotRequired. + """ + if __fields is _marker or __fields is None: + if __fields is _marker: + deprecated_thing = "Failing to pass a value for the 'fields' parameter" + else: + deprecated_thing = "Passing `None` as the 'fields' parameter" + + example = f"`{__typename} = TypedDict({__typename!r}, {{}})`" + deprecation_msg = ( + f"{deprecated_thing} is deprecated and will be disallowed in " + "Python 3.15. To create a TypedDict class with 0 fields " + "using the functional syntax, pass an empty dictionary, e.g. " + ) + example + "." + warnings.warn(deprecation_msg, DeprecationWarning, stacklevel=2) + __fields = kwargs + elif kwargs: + raise TypeError("TypedDict takes either a dict or keyword arguments," + " but not both") + if kwargs: + warnings.warn( + "The kwargs-based syntax for TypedDict definitions is deprecated " + "in Python 3.11, will be removed in Python 3.13, and may not be " + "understood by third-party type checkers.", + DeprecationWarning, + stacklevel=2, + ) + + ns = {'__annotations__': dict(__fields)} + module = _caller() + if module is not None: + # Setting correct module is necessary to make typed dict classes pickleable. + ns['__module__'] = module + + td = _TypedDictMeta(__typename, (), ns, total=total) + td.__orig_bases__ = (TypedDict,) + return td + + if hasattr(typing, "_TypedDictMeta"): + _TYPEDDICT_TYPES = (typing._TypedDictMeta, _TypedDictMeta) + else: + _TYPEDDICT_TYPES = (_TypedDictMeta,) + + def is_typeddict(tp): + """Check if an annotation is a TypedDict class + + For example:: + class Film(TypedDict): + title: str + year: int + + is_typeddict(Film) # => True + is_typeddict(Union[list, str]) # => False + """ + # On 3.8, this would otherwise return True + if hasattr(typing, "TypedDict") and tp is typing.TypedDict: + return False + return isinstance(tp, _TYPEDDICT_TYPES) + + +if hasattr(typing, "assert_type"): + assert_type = typing.assert_type + +else: + def assert_type(__val, __typ): + """Assert (to the type checker) that the value is of the given type. + + When the type checker encounters a call to assert_type(), it + emits an error if the value is not of the specified type:: + + def greet(name: str) -> None: + assert_type(name, str) # ok + assert_type(name, int) # type checker error + + At runtime this returns the first argument unchanged and otherwise + does nothing. + """ + return __val + + +if hasattr(typing, "Required"): + get_type_hints = typing.get_type_hints +else: + # replaces _strip_annotations() + def _strip_extras(t): + """Strips Annotated, Required and NotRequired from a given type.""" + if isinstance(t, _AnnotatedAlias): + return _strip_extras(t.__origin__) + if hasattr(t, "__origin__") and t.__origin__ in (Required, NotRequired): + return _strip_extras(t.__args__[0]) + if isinstance(t, typing._GenericAlias): + stripped_args = tuple(_strip_extras(a) for a in t.__args__) + if stripped_args == t.__args__: + return t + return t.copy_with(stripped_args) + if hasattr(_types, "GenericAlias") and isinstance(t, _types.GenericAlias): + stripped_args = tuple(_strip_extras(a) for a in t.__args__) + if stripped_args == t.__args__: + return t + return _types.GenericAlias(t.__origin__, stripped_args) + if hasattr(_types, "UnionType") and isinstance(t, _types.UnionType): + stripped_args = tuple(_strip_extras(a) for a in t.__args__) + if stripped_args == t.__args__: + return t + return functools.reduce(operator.or_, stripped_args) + + return t + + def get_type_hints(obj, globalns=None, localns=None, include_extras=False): + """Return type hints for an object. + + This is often the same as obj.__annotations__, but it handles + forward references encoded as string literals, adds Optional[t] if a + default value equal to None is set and recursively replaces all + 'Annotated[T, ...]', 'Required[T]' or 'NotRequired[T]' with 'T' + (unless 'include_extras=True'). + + The argument may be a module, class, method, or function. The annotations + are returned as a dictionary. For classes, annotations include also + inherited members. + + TypeError is raised if the argument is not of a type that can contain + annotations, and an empty dictionary is returned if no annotations are + present. + + BEWARE -- the behavior of globalns and localns is counterintuitive + (unless you are familiar with how eval() and exec() work). The + search order is locals first, then globals. + + - If no dict arguments are passed, an attempt is made to use the + globals from obj (or the respective module's globals for classes), + and these are also used as the locals. If the object does not appear + to have globals, an empty dictionary is used. + + - If one dict argument is passed, it is used for both globals and + locals. + + - If two dict arguments are passed, they specify globals and + locals, respectively. + """ + if hasattr(typing, "Annotated"): + hint = typing.get_type_hints( + obj, globalns=globalns, localns=localns, include_extras=True + ) + else: + hint = typing.get_type_hints(obj, globalns=globalns, localns=localns) + if include_extras: + return hint + return {k: _strip_extras(t) for k, t in hint.items()} + + +# Python 3.9+ has PEP 593 (Annotated) +if hasattr(typing, 'Annotated'): + Annotated = typing.Annotated + # Not exported and not a public API, but needed for get_origin() and get_args() + # to work. + _AnnotatedAlias = typing._AnnotatedAlias +# 3.7-3.8 +else: + class _AnnotatedAlias(typing._GenericAlias, _root=True): + """Runtime representation of an annotated type. + + At its core 'Annotated[t, dec1, dec2, ...]' is an alias for the type 't' + with extra annotations. The alias behaves like a normal typing alias, + instantiating is the same as instantiating the underlying type, binding + it to types is also the same. + """ + def __init__(self, origin, metadata): + if isinstance(origin, _AnnotatedAlias): + metadata = origin.__metadata__ + metadata + origin = origin.__origin__ + super().__init__(origin, origin) + self.__metadata__ = metadata + + def copy_with(self, params): + assert len(params) == 1 + new_type = params[0] + return _AnnotatedAlias(new_type, self.__metadata__) + + def __repr__(self): + return (f"typing_extensions.Annotated[{typing._type_repr(self.__origin__)}, " + f"{', '.join(repr(a) for a in self.__metadata__)}]") + + def __reduce__(self): + return operator.getitem, ( + Annotated, (self.__origin__,) + self.__metadata__ + ) + + def __eq__(self, other): + if not isinstance(other, _AnnotatedAlias): + return NotImplemented + if self.__origin__ != other.__origin__: + return False + return self.__metadata__ == other.__metadata__ + + def __hash__(self): + return hash((self.__origin__, self.__metadata__)) + + class Annotated: + """Add context specific metadata to a type. + + Example: Annotated[int, runtime_check.Unsigned] indicates to the + hypothetical runtime_check module that this type is an unsigned int. + Every other consumer of this type can ignore this metadata and treat + this type as int. + + The first argument to Annotated must be a valid type (and will be in + the __origin__ field), the remaining arguments are kept as a tuple in + the __extra__ field. + + Details: + + - It's an error to call `Annotated` with less than two arguments. + - Nested Annotated are flattened:: + + Annotated[Annotated[T, Ann1, Ann2], Ann3] == Annotated[T, Ann1, Ann2, Ann3] + + - Instantiating an annotated type is equivalent to instantiating the + underlying type:: + + Annotated[C, Ann1](5) == C(5) + + - Annotated can be used as a generic type alias:: + + Optimized = Annotated[T, runtime.Optimize()] + Optimized[int] == Annotated[int, runtime.Optimize()] + + OptimizedList = Annotated[List[T], runtime.Optimize()] + OptimizedList[int] == Annotated[List[int], runtime.Optimize()] + """ + + __slots__ = () + + def __new__(cls, *args, **kwargs): + raise TypeError("Type Annotated cannot be instantiated.") + + @typing._tp_cache + def __class_getitem__(cls, params): + if not isinstance(params, tuple) or len(params) < 2: + raise TypeError("Annotated[...] should be used " + "with at least two arguments (a type and an " + "annotation).") + allowed_special_forms = (ClassVar, Final) + if get_origin(params[0]) in allowed_special_forms: + origin = params[0] + else: + msg = "Annotated[t, ...]: t must be a type." + origin = typing._type_check(params[0], msg) + metadata = tuple(params[1:]) + return _AnnotatedAlias(origin, metadata) + + def __init_subclass__(cls, *args, **kwargs): + raise TypeError( + f"Cannot subclass {cls.__module__}.Annotated" + ) + +# Python 3.8 has get_origin() and get_args() but those implementations aren't +# Annotated-aware, so we can't use those. Python 3.9's versions don't support +# ParamSpecArgs and ParamSpecKwargs, so only Python 3.10's versions will do. +if sys.version_info[:2] >= (3, 10): + get_origin = typing.get_origin + get_args = typing.get_args +# 3.7-3.9 +else: + try: + # 3.9+ + from typing import _BaseGenericAlias + except ImportError: + _BaseGenericAlias = typing._GenericAlias + try: + # 3.9+ + from typing import GenericAlias as _typing_GenericAlias + except ImportError: + _typing_GenericAlias = typing._GenericAlias + + def get_origin(tp): + """Get the unsubscripted version of a type. + + This supports generic types, Callable, Tuple, Union, Literal, Final, ClassVar + and Annotated. Return None for unsupported types. Examples:: + + get_origin(Literal[42]) is Literal + get_origin(int) is None + get_origin(ClassVar[int]) is ClassVar + get_origin(Generic) is Generic + get_origin(Generic[T]) is Generic + get_origin(Union[T, int]) is Union + get_origin(List[Tuple[T, T]][int]) == list + get_origin(P.args) is P + """ + if isinstance(tp, _AnnotatedAlias): + return Annotated + if isinstance(tp, (typing._GenericAlias, _typing_GenericAlias, _BaseGenericAlias, + ParamSpecArgs, ParamSpecKwargs)): + return tp.__origin__ + if tp is typing.Generic: + return typing.Generic return None - @classmethod - def __subclasshook__(cls, C): - if cls is AsyncContextManager: - return _check_methods_in_mro(C, "__aenter__", "__aexit__") - return NotImplemented + def get_args(tp): + """Get type arguments with all substitutions performed. + + For unions, basic simplifications used by Union constructor are performed. + Examples:: + get_args(Dict[str, int]) == (str, int) + get_args(int) == () + get_args(Union[int, Union[T, int], str][int]) == (int, str) + get_args(Union[int, Tuple[T, int]][str]) == (int, Tuple[str, int]) + get_args(Callable[[], T][int]) == ([], int) + """ + if isinstance(tp, _AnnotatedAlias): + return (tp.__origin__,) + tp.__metadata__ + if isinstance(tp, (typing._GenericAlias, _typing_GenericAlias)): + if getattr(tp, "_special", False): + return () + res = tp.__args__ + if get_origin(tp) is collections.abc.Callable and res[0] is not Ellipsis: + res = (list(res[:-1]), res[-1]) + return res + return () + + +# 3.10+ +if hasattr(typing, 'TypeAlias'): + TypeAlias = typing.TypeAlias +# 3.9 +elif sys.version_info[:2] >= (3, 9): + @_ExtensionsSpecialForm + def TypeAlias(self, parameters): + """Special marker indicating that an assignment should + be recognized as a proper type alias definition by type + checkers. + + For example:: + + Predicate: TypeAlias = Callable[..., bool] + + It's invalid when used anywhere except as in the example above. + """ + raise TypeError(f"{self} is not subscriptable") +# 3.7-3.8 +else: + TypeAlias = _ExtensionsSpecialForm( + 'TypeAlias', + doc="""Special marker indicating that an assignment should + be recognized as a proper type alias definition by type + checkers. + + For example:: + + Predicate: TypeAlias = Callable[..., bool] + + It's invalid when used anywhere except as in the example + above.""" + ) + + +def _set_default(type_param, default): + if isinstance(default, (tuple, list)): + type_param.__default__ = tuple((typing._type_check(d, "Default must be a type") + for d in default)) + elif default != _marker: + type_param.__default__ = typing._type_check(default, "Default must be a type") + else: + type_param.__default__ = None + + +def _set_module(typevarlike): + # for pickling: + def_mod = _caller(depth=3) + if def_mod != 'typing_extensions': + typevarlike.__module__ = def_mod + + +class _DefaultMixin: + """Mixin for TypeVarLike defaults.""" + + __slots__ = () + __init__ = _set_default + + +# Classes using this metaclass must provide a _backported_typevarlike ClassVar +class _TypeVarLikeMeta(type): + def __instancecheck__(cls, __instance: Any) -> bool: + return isinstance(__instance, cls._backported_typevarlike) + + +# Add default and infer_variance parameters from PEP 696 and 695 +class TypeVar(metaclass=_TypeVarLikeMeta): + """Type variable.""" + + _backported_typevarlike = typing.TypeVar + + def __new__(cls, name, *constraints, bound=None, + covariant=False, contravariant=False, + default=_marker, infer_variance=False): + if hasattr(typing, "TypeAliasType"): + # PEP 695 implemented, can pass infer_variance to typing.TypeVar + typevar = typing.TypeVar(name, *constraints, bound=bound, + covariant=covariant, contravariant=contravariant, + infer_variance=infer_variance) + else: + typevar = typing.TypeVar(name, *constraints, bound=bound, + covariant=covariant, contravariant=contravariant) + if infer_variance and (covariant or contravariant): + raise ValueError("Variance cannot be specified with infer_variance.") + typevar.__infer_variance__ = infer_variance + _set_default(typevar, default) + _set_module(typevar) + return typevar + + def __init_subclass__(cls) -> None: + raise TypeError(f"type '{__name__}.TypeVar' is not an acceptable base type") + + +# Python 3.10+ has PEP 612 +if hasattr(typing, 'ParamSpecArgs'): + ParamSpecArgs = typing.ParamSpecArgs + ParamSpecKwargs = typing.ParamSpecKwargs +# 3.7-3.9 +else: + class _Immutable: + """Mixin to indicate that object should not be copied.""" + __slots__ = () + + def __copy__(self): + return self + + def __deepcopy__(self, memo): + return self + + class ParamSpecArgs(_Immutable): + """The args for a ParamSpec object. + + Given a ParamSpec object P, P.args is an instance of ParamSpecArgs. + + ParamSpecArgs objects have a reference back to their ParamSpec: + + P.args.__origin__ is P + + This type is meant for runtime introspection and has no special meaning to + static type checkers. + """ + def __init__(self, origin): + self.__origin__ = origin + + def __repr__(self): + return f"{self.__origin__.__name__}.args" + + def __eq__(self, other): + if not isinstance(other, ParamSpecArgs): + return NotImplemented + return self.__origin__ == other.__origin__ + + class ParamSpecKwargs(_Immutable): + """The kwargs for a ParamSpec object. + + Given a ParamSpec object P, P.kwargs is an instance of ParamSpecKwargs. + + ParamSpecKwargs objects have a reference back to their ParamSpec: + + P.kwargs.__origin__ is P + + This type is meant for runtime introspection and has no special meaning to + static type checkers. + """ + def __init__(self, origin): + self.__origin__ = origin + + def __repr__(self): + return f"{self.__origin__.__name__}.kwargs" + + def __eq__(self, other): + if not isinstance(other, ParamSpecKwargs): + return NotImplemented + return self.__origin__ == other.__origin__ + +# 3.10+ +if hasattr(typing, 'ParamSpec'): + + # Add default parameter - PEP 696 + class ParamSpec(metaclass=_TypeVarLikeMeta): + """Parameter specification.""" + + _backported_typevarlike = typing.ParamSpec + + def __new__(cls, name, *, bound=None, + covariant=False, contravariant=False, + infer_variance=False, default=_marker): + if hasattr(typing, "TypeAliasType"): + # PEP 695 implemented, can pass infer_variance to typing.TypeVar + paramspec = typing.ParamSpec(name, bound=bound, + covariant=covariant, + contravariant=contravariant, + infer_variance=infer_variance) + else: + paramspec = typing.ParamSpec(name, bound=bound, + covariant=covariant, + contravariant=contravariant) + paramspec.__infer_variance__ = infer_variance + + _set_default(paramspec, default) + _set_module(paramspec) + return paramspec + + def __init_subclass__(cls) -> None: + raise TypeError(f"type '{__name__}.ParamSpec' is not an acceptable base type") + +# 3.7-3.9 +else: + + # Inherits from list as a workaround for Callable checks in Python < 3.9.2. + class ParamSpec(list, _DefaultMixin): + """Parameter specification variable. + + Usage:: + + P = ParamSpec('P') + + Parameter specification variables exist primarily for the benefit of static + type checkers. They are used to forward the parameter types of one + callable to another callable, a pattern commonly found in higher order + functions and decorators. They are only valid when used in ``Concatenate``, + or s the first argument to ``Callable``. In Python 3.10 and higher, + they are also supported in user-defined Generics at runtime. + See class Generic for more information on generic types. An + example for annotating a decorator:: + + T = TypeVar('T') + P = ParamSpec('P') + + def add_logging(f: Callable[P, T]) -> Callable[P, T]: + '''A type-safe decorator to add logging to a function.''' + def inner(*args: P.args, **kwargs: P.kwargs) -> T: + logging.info(f'{f.__name__} was called') + return f(*args, **kwargs) + return inner + + @add_logging + def add_two(x: float, y: float) -> float: + '''Add two numbers together.''' + return x + y + + Parameter specification variables defined with covariant=True or + contravariant=True can be used to declare covariant or contravariant + generic types. These keyword arguments are valid, but their actual semantics + are yet to be decided. See PEP 612 for details. + + Parameter specification variables can be introspected. e.g.: + + P.__name__ == 'T' + P.__bound__ == None + P.__covariant__ == False + P.__contravariant__ == False + + Note that only parameter specification variables defined in global scope can + be pickled. + """ + + # Trick Generic __parameters__. + __class__ = typing.TypeVar + + @property + def args(self): + return ParamSpecArgs(self) + + @property + def kwargs(self): + return ParamSpecKwargs(self) + + def __init__(self, name, *, bound=None, covariant=False, contravariant=False, + infer_variance=False, default=_marker): + super().__init__([self]) + self.__name__ = name + self.__covariant__ = bool(covariant) + self.__contravariant__ = bool(contravariant) + self.__infer_variance__ = bool(infer_variance) + if bound: + self.__bound__ = typing._type_check(bound, 'Bound must be a type.') + else: + self.__bound__ = None + _DefaultMixin.__init__(self, default) + + # for pickling: + def_mod = _caller() + if def_mod != 'typing_extensions': + self.__module__ = def_mod + + def __repr__(self): + if self.__infer_variance__: + prefix = '' + elif self.__covariant__: + prefix = '+' + elif self.__contravariant__: + prefix = '-' + else: + prefix = '~' + return prefix + self.__name__ + + def __hash__(self): + return object.__hash__(self) + + def __eq__(self, other): + return self is other + + def __reduce__(self): + return self.__name__ + + # Hack to get typing._type_check to pass. + def __call__(self, *args, **kwargs): + pass + -__all__.append('AsyncContextManager') -""") +# 3.7-3.9 +if not hasattr(typing, 'Concatenate'): + # Inherits from list as a workaround for Callable checks in Python < 3.9.2. + class _ConcatenateGenericAlias(list): + # Trick Generic into looking into this for __parameters__. + __class__ = typing._GenericAlias -if hasattr(typing, 'DefaultDict'): - DefaultDict = typing.DefaultDict -elif _geqv_defined: - class DefaultDict(collections.defaultdict, typing.MutableMapping[KT, VT], - metaclass=_ExtensionsGenericMeta, - extra=collections.defaultdict): + # Flag in 3.8. + _special = False - __slots__ = () + def __init__(self, origin, args): + super().__init__(args) + self.__origin__ = origin + self.__args__ = args - def __new__(cls, *args, **kwds): - if _geqv(cls, DefaultDict): - return collections.defaultdict(*args, **kwds) - return _generic_new(collections.defaultdict, cls, *args, **kwds) -else: - class DefaultDict(collections.defaultdict, typing.MutableMapping[KT, VT], - metaclass=_ExtensionsGenericMeta, - extra=collections.defaultdict): + def __repr__(self): + _type_repr = typing._type_repr + return (f'{_type_repr(self.__origin__)}' + f'[{", ".join(_type_repr(arg) for arg in self.__args__)}]') - __slots__ = () + def __hash__(self): + return hash((self.__origin__, self.__args__)) - def __new__(cls, *args, **kwds): - if cls._gorg is DefaultDict: - return collections.defaultdict(*args, **kwds) - return _generic_new(collections.defaultdict, cls, *args, **kwds) + # Hack to get typing._type_check to pass in Generic. + def __call__(self, *args, **kwargs): + pass + @property + def __parameters__(self): + return tuple( + tp for tp in self.__args__ if isinstance(tp, (typing.TypeVar, ParamSpec)) + ) -if hasattr(typing, 'Counter'): - Counter = typing.Counter -elif (3, 5, 0) <= sys.version_info[:3] <= (3, 5, 1): - assert _geqv_defined - _TInt = typing.TypeVar('_TInt') - class _CounterMeta(typing.GenericMeta): - """Metaclass for Counter""" - def __getitem__(self, item): - return super().__getitem__((item, int)) +# 3.7-3.9 +@typing._tp_cache +def _concatenate_getitem(self, parameters): + if parameters == (): + raise TypeError("Cannot take a Concatenate of no types.") + if not isinstance(parameters, tuple): + parameters = (parameters,) + if not isinstance(parameters[-1], ParamSpec): + raise TypeError("The last parameter to Concatenate should be a " + "ParamSpec variable.") + msg = "Concatenate[arg, ...]: each arg must be a type." + parameters = tuple(typing._type_check(p, msg) for p in parameters) + return _ConcatenateGenericAlias(self, parameters) + + +# 3.10+ +if hasattr(typing, 'Concatenate'): + Concatenate = typing.Concatenate + _ConcatenateGenericAlias = typing._ConcatenateGenericAlias # noqa: F811 +# 3.9 +elif sys.version_info[:2] >= (3, 9): + @_ExtensionsSpecialForm + def Concatenate(self, parameters): + """Used in conjunction with ``ParamSpec`` and ``Callable`` to represent a + higher order function which adds, removes or transforms parameters of a + callable. - class Counter(collections.Counter, - typing.Dict[T, int], - metaclass=_CounterMeta, - extra=collections.Counter): + For example:: - __slots__ = () + Callable[Concatenate[int, P], int] - def __new__(cls, *args, **kwds): - if _geqv(cls, Counter): - return collections.Counter(*args, **kwds) - return _generic_new(collections.Counter, cls, *args, **kwds) + See PEP 612 for detailed information. + """ + return _concatenate_getitem(self, parameters) +# 3.7-8 +else: + class _ConcatenateForm(_ExtensionsSpecialForm, _root=True): + def __getitem__(self, parameters): + return _concatenate_getitem(self, parameters) -elif _geqv_defined: - class Counter(collections.Counter, - typing.Dict[T, int], - metaclass=_ExtensionsGenericMeta, extra=collections.Counter): + Concatenate = _ConcatenateForm( + 'Concatenate', + doc="""Used in conjunction with ``ParamSpec`` and ``Callable`` to represent a + higher order function which adds, removes or transforms parameters of a + callable. - __slots__ = () + For example:: - def __new__(cls, *args, **kwds): - if _geqv(cls, Counter): - return collections.Counter(*args, **kwds) - return _generic_new(collections.Counter, cls, *args, **kwds) + Callable[Concatenate[int, P], int] -else: - class Counter(collections.Counter, - typing.Dict[T, int], - metaclass=_ExtensionsGenericMeta, extra=collections.Counter): + See PEP 612 for detailed information. + """) - __slots__ = () +# 3.10+ +if hasattr(typing, 'TypeGuard'): + TypeGuard = typing.TypeGuard +# 3.9 +elif sys.version_info[:2] >= (3, 9): + @_ExtensionsSpecialForm + def TypeGuard(self, parameters): + """Special typing form used to annotate the return type of a user-defined + type guard function. ``TypeGuard`` only accepts a single type argument. + At runtime, functions marked this way should return a boolean. - def __new__(cls, *args, **kwds): - if cls._gorg is Counter: - return collections.Counter(*args, **kwds) - return _generic_new(collections.Counter, cls, *args, **kwds) + ``TypeGuard`` aims to benefit *type narrowing* -- a technique used by static + type checkers to determine a more precise type of an expression within a + program's code flow. Usually type narrowing is done by analyzing + conditional code flow and applying the narrowing to a block of code. The + conditional expression here is sometimes referred to as a "type guard". + Sometimes it would be convenient to use a user-defined boolean function + as a type guard. Such a function should use ``TypeGuard[...]`` as its + return type to alert static type checkers to this intention. -if hasattr(typing, 'ChainMap'): - ChainMap = typing.ChainMap - __all__.append('ChainMap') -elif hasattr(collections, 'ChainMap'): - # ChainMap only exists in 3.3+ - if _geqv_defined: - class ChainMap(collections.ChainMap, typing.MutableMapping[KT, VT], - metaclass=_ExtensionsGenericMeta, - extra=collections.ChainMap): + Using ``-> TypeGuard`` tells the static type checker that for a given + function: - __slots__ = () + 1. The return value is a boolean. + 2. If the return value is ``True``, the type of its argument + is the type inside ``TypeGuard``. - def __new__(cls, *args, **kwds): - if _geqv(cls, ChainMap): - return collections.ChainMap(*args, **kwds) - return _generic_new(collections.ChainMap, cls, *args, **kwds) - else: - class ChainMap(collections.ChainMap, typing.MutableMapping[KT, VT], - metaclass=_ExtensionsGenericMeta, - extra=collections.ChainMap): + For example:: - __slots__ = () + def is_str(val: Union[str, float]): + # "isinstance" type guard + if isinstance(val, str): + # Type of ``val`` is narrowed to ``str`` + ... + else: + # Else, type of ``val`` is narrowed to ``float``. + ... - def __new__(cls, *args, **kwds): - if cls._gorg is ChainMap: - return collections.ChainMap(*args, **kwds) - return _generic_new(collections.ChainMap, cls, *args, **kwds) + Strict type narrowing is not enforced -- ``TypeB`` need not be a narrower + form of ``TypeA`` (it can even be a wider form) and this may lead to + type-unsafe results. The main reason is to allow for things like + narrowing ``List[object]`` to ``List[str]`` even though the latter is not + a subtype of the former, since ``List`` is invariant. The responsibility of + writing type-safe type guards is left to the user. - __all__.append('ChainMap') + ``TypeGuard`` also works with type variables. For more information, see + PEP 647 (User-Defined Type Guards). + """ + item = typing._type_check(parameters, f'{self} accepts only a single type.') + return typing._GenericAlias(self, (item,)) +# 3.7-3.8 +else: + class _TypeGuardForm(_ExtensionsSpecialForm, _root=True): + def __getitem__(self, parameters): + item = typing._type_check(parameters, + f'{self._name} accepts only a single type') + return typing._GenericAlias(self, (item,)) + TypeGuard = _TypeGuardForm( + 'TypeGuard', + doc="""Special typing form used to annotate the return type of a user-defined + type guard function. ``TypeGuard`` only accepts a single type argument. + At runtime, functions marked this way should return a boolean. -if _define_guard('AsyncGenerator'): - class AsyncGenerator(AsyncIterator[T_co], typing.Generic[T_co, T_contra], - metaclass=_ExtensionsGenericMeta, - extra=collections_abc.AsyncGenerator): - __slots__ = () + ``TypeGuard`` aims to benefit *type narrowing* -- a technique used by static + type checkers to determine a more precise type of an expression within a + program's code flow. Usually type narrowing is done by analyzing + conditional code flow and applying the narrowing to a block of code. The + conditional expression here is sometimes referred to as a "type guard". + Sometimes it would be convenient to use a user-defined boolean function + as a type guard. Such a function should use ``TypeGuard[...]`` as its + return type to alert static type checkers to this intention. -if hasattr(typing, 'NewType'): - NewType = typing.NewType -else: - def NewType(name, tp): - """NewType creates simple unique types with almost zero - runtime overhead. NewType(name, tp) is considered a subtype of tp - by static type checkers. At runtime, NewType(name, tp) returns - a dummy function that simply returns its argument. Usage:: + Using ``-> TypeGuard`` tells the static type checker that for a given + function: - UserId = NewType('UserId', int) + 1. The return value is a boolean. + 2. If the return value is ``True``, the type of its argument + is the type inside ``TypeGuard``. - def name_by_id(user_id: UserId) -> str: - ... + For example:: - UserId('user') # Fails type check + def is_str(val: Union[str, float]): + # "isinstance" type guard + if isinstance(val, str): + # Type of ``val`` is narrowed to ``str`` + ... + else: + # Else, type of ``val`` is narrowed to ``float``. + ... - name_by_id(42) # Fails type check - name_by_id(UserId(42)) # OK + Strict type narrowing is not enforced -- ``TypeB`` need not be a narrower + form of ``TypeA`` (it can even be a wider form) and this may lead to + type-unsafe results. The main reason is to allow for things like + narrowing ``List[object]`` to ``List[str]`` even though the latter is not + a subtype of the former, since ``List`` is invariant. The responsibility of + writing type-safe type guards is left to the user. - num = UserId(5) + 1 # type: int - """ + ``TypeGuard`` also works with type variables. For more information, see + PEP 647 (User-Defined Type Guards). + """) - def new_type(x): - return x - new_type.__name__ = name - new_type.__supertype__ = tp - return new_type +# Vendored from cpython typing._SpecialFrom +class _SpecialForm(typing._Final, _root=True): + __slots__ = ('_name', '__doc__', '_getitem') + def __init__(self, getitem): + self._getitem = getitem + self._name = getitem.__name__ + self.__doc__ = getitem.__doc__ -if hasattr(typing, 'Text'): - Text = typing.Text -else: - Text = str + def __getattr__(self, item): + if item in {'__name__', '__qualname__'}: + return self._name + raise AttributeError(item) -if hasattr(typing, 'TYPE_CHECKING'): - TYPE_CHECKING = typing.TYPE_CHECKING -else: - # Constant that's True when type checking, but False here. - TYPE_CHECKING = False + def __mro_entries__(self, bases): + raise TypeError(f"Cannot subclass {self!r}") + def __repr__(self): + return f'typing_extensions.{self._name}' -def _gorg(cls): - """This function exists for compatibility with old typing versions.""" - assert isinstance(cls, GenericMeta) - if hasattr(cls, '_gorg'): - return cls._gorg - while cls.__origin__ is not None: - cls = cls.__origin__ - return cls + def __reduce__(self): + return self._name + def __call__(self, *args, **kwds): + raise TypeError(f"Cannot instantiate {self!r}") -if OLD_GENERICS: - def _next_in_mro(cls): # noqa - """This function exists for compatibility with old typing versions.""" - next_in_mro = object - for i, c in enumerate(cls.__mro__[:-1]): - if isinstance(c, GenericMeta) and _gorg(c) is Generic: - next_in_mro = cls.__mro__[i + 1] - return next_in_mro + def __or__(self, other): + return typing.Union[self, other] + def __ror__(self, other): + return typing.Union[other, self] -_PROTO_WHITELIST = ['Callable', 'Awaitable', - 'Iterable', 'Iterator', 'AsyncIterable', 'AsyncIterator', - 'Hashable', 'Sized', 'Container', 'Collection', 'Reversible', - 'ContextManager', 'AsyncContextManager'] + def __instancecheck__(self, obj): + raise TypeError(f"{self} cannot be used with isinstance()") + def __subclasscheck__(self, cls): + raise TypeError(f"{self} cannot be used with issubclass()") -def _get_protocol_attrs(cls): - attrs = set() - for base in cls.__mro__[:-1]: # without object - if base.__name__ in ('Protocol', 'Generic'): - continue - annotations = getattr(base, '__annotations__', {}) - for attr in list(base.__dict__.keys()) + list(annotations.keys()): - if (not attr.startswith('_abc_') and attr not in ( - '__abstractmethods__', '__annotations__', '__weakref__', - '_is_protocol', '_is_runtime_protocol', '__dict__', - '__args__', '__slots__', - '__next_in_mro__', '__parameters__', '__origin__', - '__orig_bases__', '__extra__', '__tree_hash__', - '__doc__', '__subclasshook__', '__init__', '__new__', - '__module__', '_MutableMapping__marker', '_gorg')): - attrs.add(attr) - return attrs + @typing._tp_cache + def __getitem__(self, parameters): + return self._getitem(self, parameters) -def _is_callable_members_only(cls): - return all(callable(getattr(cls, attr, None)) for attr in _get_protocol_attrs(cls)) +if hasattr(typing, "LiteralString"): + LiteralString = typing.LiteralString +else: + @_SpecialForm + def LiteralString(self, params): + """Represents an arbitrary literal string. + Example:: -if hasattr(typing, 'Protocol'): - Protocol = typing.Protocol -elif HAVE_PROTOCOLS and not PEP_560: - class _ProtocolMeta(GenericMeta): - """Internal metaclass for Protocol. + from typing_extensions import LiteralString + + def query(sql: LiteralString) -> ...: + ... + + query("SELECT * FROM table") # ok + query(f"SELECT * FROM {input()}") # not ok + + See PEP 675 for details. - This exists so Protocol classes can be generic without deriving - from Generic. """ - if not OLD_GENERICS: - def __new__(cls, name, bases, namespace, - tvars=None, args=None, origin=None, extra=None, orig_bases=None): - # This is just a version copied from GenericMeta.__new__ that - # includes "Protocol" special treatment. (Comments removed for brevity.) - assert extra is None # Protocols should not have extra - if tvars is not None: - assert origin is not None - assert all(isinstance(t, TypeVar) for t in tvars), tvars - else: - tvars = _type_vars(bases) - gvars = None - for base in bases: - if base is Generic: - raise TypeError("Cannot inherit from plain Generic") - if (isinstance(base, GenericMeta) and - base.__origin__ in (Generic, Protocol)): - if gvars is not None: - raise TypeError( - "Cannot inherit from Generic[...] or" - " Protocol[...] multiple times.") - gvars = base.__parameters__ - if gvars is None: - gvars = tvars - else: - tvarset = set(tvars) - gvarset = set(gvars) - if not tvarset <= gvarset: - raise TypeError( - "Some type variables (%s) " - "are not listed in %s[%s]" % - (", ".join(str(t) for t in tvars if t not in gvarset), - "Generic" if any(b.__origin__ is Generic - for b in bases) else "Protocol", - ", ".join(str(g) for g in gvars))) - tvars = gvars - - initial_bases = bases - if (extra is not None and type(extra) is abc.ABCMeta and - extra not in bases): - bases = (extra,) + bases - bases = tuple(_gorg(b) if isinstance(b, GenericMeta) else b - for b in bases) - if any(isinstance(b, GenericMeta) and b is not Generic for b in bases): - bases = tuple(b for b in bases if b is not Generic) - namespace.update({'__origin__': origin, '__extra__': extra}) - self = super(GenericMeta, cls).__new__(cls, name, bases, namespace, - _root=True) - super(GenericMeta, self).__setattr__('_gorg', - self if not origin else - _gorg(origin)) - self.__parameters__ = tvars - self.__args__ = tuple(... if a is _TypingEllipsis else - () if a is _TypingEmpty else - a for a in args) if args else None - self.__next_in_mro__ = _next_in_mro(self) - if orig_bases is None: - self.__orig_bases__ = initial_bases - elif origin is not None: - self._abc_registry = origin._abc_registry - self._abc_cache = origin._abc_cache - if hasattr(self, '_subs_tree'): - self.__tree_hash__ = (hash(self._subs_tree()) if origin else - super(GenericMeta, self).__hash__()) - return self + raise TypeError(f"{self} is not subscriptable") - def __init__(cls, *args, **kwargs): - super().__init__(*args, **kwargs) - if not cls.__dict__.get('_is_protocol', None): - cls._is_protocol = any(b is Protocol or - isinstance(b, _ProtocolMeta) and - b.__origin__ is Protocol - for b in cls.__bases__) - if cls._is_protocol: - for base in cls.__mro__[1:]: - if not (base in (object, Generic) or - base.__module__ == 'collections.abc' and - base.__name__ in _PROTO_WHITELIST or - isinstance(base, TypingMeta) and base._is_protocol or - isinstance(base, GenericMeta) and - base.__origin__ is Generic): - raise TypeError('Protocols can only inherit from other' - ' protocols, got %r' % base) - - def _no_init(self, *args, **kwargs): - if type(self)._is_protocol: - raise TypeError('Protocols cannot be instantiated') - cls.__init__ = _no_init - - def _proto_hook(other): - if not cls.__dict__.get('_is_protocol', None): - return NotImplemented - if not isinstance(other, type): - # Same error as for issubclass(1, int) - raise TypeError('issubclass() arg 1 must be a class') - for attr in _get_protocol_attrs(cls): - for base in other.__mro__: - if attr in base.__dict__: - if base.__dict__[attr] is None: - return NotImplemented - break - annotations = getattr(base, '__annotations__', {}) - if (isinstance(annotations, typing.Mapping) and - attr in annotations and - isinstance(other, _ProtocolMeta) and - other._is_protocol): - break - else: - return NotImplemented - return True - if '__subclasshook__' not in cls.__dict__: - cls.__subclasshook__ = _proto_hook - def __instancecheck__(self, instance): - # We need this method for situations where attributes are - # assigned in __init__. - if ((not getattr(self, '_is_protocol', False) or - _is_callable_members_only(self)) and - issubclass(instance.__class__, self)): - return True - if self._is_protocol: - if all(hasattr(instance, attr) and - (not callable(getattr(self, attr, None)) or - getattr(instance, attr) is not None) - for attr in _get_protocol_attrs(self)): - return True - return super(GenericMeta, self).__instancecheck__(instance) - - def __subclasscheck__(self, cls): - if self.__origin__ is not None: - if sys._getframe(1).f_globals['__name__'] not in ['abc', 'functools']: - raise TypeError("Parameterized generics cannot be used with class " - "or instance checks") - return False - if (self.__dict__.get('_is_protocol', None) and - not self.__dict__.get('_is_runtime_protocol', None)): - if sys._getframe(1).f_globals['__name__'] in ['abc', - 'functools', - 'typing']: - return False - raise TypeError("Instance and class checks can only be used with" - " @runtime protocols") - if (self.__dict__.get('_is_runtime_protocol', None) and - not _is_callable_members_only(self)): - if sys._getframe(1).f_globals['__name__'] in ['abc', - 'functools', - 'typing']: - return super(GenericMeta, self).__subclasscheck__(cls) - raise TypeError("Protocols with non-method members" - " don't support issubclass()") - return super(GenericMeta, self).__subclasscheck__(cls) - - if not OLD_GENERICS: - @_tp_cache - def __getitem__(self, params): - # We also need to copy this from GenericMeta.__getitem__ to get - # special treatment of "Protocol". (Comments removed for brevity.) - if not isinstance(params, tuple): - params = (params,) - if not params and _gorg(self) is not Tuple: - raise TypeError( - "Parameter list to %s[...] cannot be empty" % self.__qualname__) - msg = "Parameters to generic types must be types." - params = tuple(_type_check(p, msg) for p in params) - if self in (Generic, Protocol): - if not all(isinstance(p, TypeVar) for p in params): - raise TypeError( - "Parameters to %r[...] must all be type variables" % self) - if len(set(params)) != len(params): - raise TypeError( - "Parameters to %r[...] must all be unique" % self) - tvars = params - args = params - elif self in (Tuple, Callable): - tvars = _type_vars(params) - args = params - elif self.__origin__ in (Generic, Protocol): - raise TypeError("Cannot subscript already-subscripted %s" % - repr(self)) - else: - _check_generic(self, params) - tvars = _type_vars(params) - args = params - - prepend = (self,) if self.__origin__ is None else () - return self.__class__(self.__name__, - prepend + self.__bases__, - _no_slots_copy(self.__dict__), - tvars=tvars, - args=args, - origin=self, - extra=self.__extra__, - orig_bases=self.__orig_bases__) - - class Protocol(metaclass=_ProtocolMeta): - """Base class for protocol classes. Protocol classes are defined as:: - - class Proto(Protocol): - def meth(self) -> int: +if hasattr(typing, "Self"): + Self = typing.Self +else: + @_SpecialForm + def Self(self, params): + """Used to spell the type of "self" in classes. + + Example:: + + from typing import Self + + class ReturnsSelf: + def parse(self, data: bytes) -> Self: ... + return self + + """ - Such classes are primarily used with static type checkers that recognize - structural subtyping (static duck-typing), for example:: + raise TypeError(f"{self} is not subscriptable") - class C: - def meth(self) -> int: - return 0 - def func(x: Proto) -> int: - return x.meth() +if hasattr(typing, "Never"): + Never = typing.Never +else: + @_SpecialForm + def Never(self, params): + """The bottom type, a type that has no members. - func(C()) # Passes static type check + This can be used to define a function that should never be + called, or a function that never returns:: - See PEP 544 for details. Protocol classes decorated with - @typing_extensions.runtime act as simple-minded runtime protocol that checks - only the presence of given attributes, ignoring their type signatures. + from typing_extensions import Never - Protocol classes can be generic, they are defined as:: + def never_call_me(arg: Never) -> None: + pass + + def int_or_str(arg: int | str) -> None: + never_call_me(arg) # type checker error + match arg: + case int(): + print("It's an int") + case str(): + print("It's a str") + case _: + never_call_me(arg) # ok, arg is of type Never - class GenProto({bases}): - def meth(self) -> T: - ... """ - __slots__ = () - _is_protocol = True - - def __new__(cls, *args, **kwds): - if _gorg(cls) is Protocol: - raise TypeError("Type Protocol cannot be instantiated; " - "it can be used only as a base class") - if OLD_GENERICS: - return _generic_new(_next_in_mro(cls), cls, *args, **kwds) - return _generic_new(cls.__next_in_mro__, cls, *args, **kwds) - if Protocol.__doc__ is not None: - Protocol.__doc__ = Protocol.__doc__.format(bases="Protocol, Generic[T]" if - OLD_GENERICS else "Protocol[T]") - - -elif PEP_560: - from typing import _type_check, _GenericAlias, _collect_type_vars # noqa - - class _ProtocolMeta(abc.ABCMeta): - # This metaclass is a bit unfortunate and exists only because of the lack - # of __instancehook__. - def __instancecheck__(cls, instance): - # We need this method for situations where attributes are - # assigned in __init__. - if ((not getattr(cls, '_is_protocol', False) or - _is_callable_members_only(cls)) and - issubclass(instance.__class__, cls)): - return True - if cls._is_protocol: - if all(hasattr(instance, attr) and - (not callable(getattr(cls, attr, None)) or - getattr(instance, attr) is not None) - for attr in _get_protocol_attrs(cls)): - return True - return super().__instancecheck__(instance) - - class Protocol(metaclass=_ProtocolMeta): - # There is quite a lot of overlapping code with typing.Generic. - # Unfortunately it is hard to avoid this while these live in two different - # modules. The duplicated code will be removed when Protocol is moved to typing. - """Base class for protocol classes. Protocol classes are defined as:: - - class Proto(Protocol): - def meth(self) -> int: - ... - Such classes are primarily used with static type checkers that recognize - structural subtyping (static duck-typing), for example:: + raise TypeError(f"{self} is not subscriptable") - class C: - def meth(self) -> int: - return 0 - def func(x: Proto) -> int: - return x.meth() +if hasattr(typing, 'Required'): + Required = typing.Required + NotRequired = typing.NotRequired +elif sys.version_info[:2] >= (3, 9): + @_ExtensionsSpecialForm + def Required(self, parameters): + """A special typing construct to mark a key of a total=False TypedDict + as required. For example: + + class Movie(TypedDict, total=False): + title: Required[str] + year: int + + m = Movie( + title='The Matrix', # typechecker error if key is omitted + year=1999, + ) - func(C()) # Passes static type check + There is no runtime checking that a required key is actually provided + when instantiating a related TypedDict. + """ + item = typing._type_check(parameters, f'{self._name} accepts only a single type.') + return typing._GenericAlias(self, (item,)) - See PEP 544 for details. Protocol classes decorated with - @typing_extensions.runtime act as simple-minded runtime protocol that checks - only the presence of given attributes, ignoring their type signatures. + @_ExtensionsSpecialForm + def NotRequired(self, parameters): + """A special typing construct to mark a key of a TypedDict as + potentially missing. For example: - Protocol classes can be generic, they are defined as:: + class Movie(TypedDict): + title: str + year: NotRequired[int] - class GenProto(Protocol[T]): - def meth(self) -> T: - ... + m = Movie( + title='The Matrix', # typechecker error if key is omitted + year=1999, + ) """ - __slots__ = () - _is_protocol = True + item = typing._type_check(parameters, f'{self._name} accepts only a single type.') + return typing._GenericAlias(self, (item,)) - def __new__(cls, *args, **kwds): - if cls is Protocol: - raise TypeError("Type Protocol cannot be instantiated; " - "it can only be used as a base class") - return super().__new__(cls) +else: + class _RequiredForm(_ExtensionsSpecialForm, _root=True): + def __getitem__(self, parameters): + item = typing._type_check(parameters, + f'{self._name} accepts only a single type.') + return typing._GenericAlias(self, (item,)) - @_tp_cache - def __class_getitem__(cls, params): - if not isinstance(params, tuple): - params = (params,) - if not params and cls is not Tuple: - raise TypeError( - "Parameter list to {}[...] cannot be empty".format(cls.__qualname__)) - msg = "Parameters to generic types must be types." - params = tuple(_type_check(p, msg) for p in params) - if cls is Protocol: - # Generic can only be subscripted with unique type variables. - if not all(isinstance(p, TypeVar) for p in params): - i = 0 - while isinstance(params[i], TypeVar): - i += 1 - raise TypeError( - "Parameters to Protocol[...] must all be type variables." - " Parameter {} is {}".format(i + 1, params[i])) - if len(set(params)) != len(params): - raise TypeError( - "Parameters to Protocol[...] must all be unique") - else: - # Subscripting a regular Generic subclass. - _check_generic(cls, params) - return _GenericAlias(cls, params) + Required = _RequiredForm( + 'Required', + doc="""A special typing construct to mark a key of a total=False TypedDict + as required. For example: - def __init_subclass__(cls, *args, **kwargs): - tvars = [] - if '__orig_bases__' in cls.__dict__: - error = Generic in cls.__orig_bases__ - else: - error = Generic in cls.__bases__ - if error: - raise TypeError("Cannot inherit from plain Generic") - if '__orig_bases__' in cls.__dict__: - tvars = _collect_type_vars(cls.__orig_bases__) - # Look for Generic[T1, ..., Tn] or Protocol[T1, ..., Tn]. - # If found, tvars must be a subset of it. - # If not found, tvars is it. - # Also check for and reject plain Generic, - # and reject multiple Generic[...] and/or Protocol[...]. - gvars = None - for base in cls.__orig_bases__: - if (isinstance(base, _GenericAlias) and - base.__origin__ in (Generic, Protocol)): - # for error messages - the_base = 'Generic' if base.__origin__ is Generic else 'Protocol' - if gvars is not None: - raise TypeError( - "Cannot inherit from Generic[...]" - " and/or Protocol[...] multiple types.") - gvars = base.__parameters__ - if gvars is None: - gvars = tvars - else: - tvarset = set(tvars) - gvarset = set(gvars) - if not tvarset <= gvarset: - s_vars = ', '.join(str(t) for t in tvars if t not in gvarset) - s_args = ', '.join(str(g) for g in gvars) - raise TypeError("Some type variables ({}) are" - " not listed in {}[{}]".format(s_vars, - the_base, s_args)) - tvars = gvars - cls.__parameters__ = tuple(tvars) - - # Determine if this is a protocol or a concrete subclass. - if not cls.__dict__.get('_is_protocol', None): - cls._is_protocol = any(b is Protocol for b in cls.__bases__) - - # Set (or override) the protocol subclass hook. - def _proto_hook(other): - if not cls.__dict__.get('_is_protocol', None): - return NotImplemented - if not getattr(cls, '_is_runtime_protocol', False): - if sys._getframe(2).f_globals['__name__'] in ['abc', 'functools']: - return NotImplemented - raise TypeError("Instance and class checks can only be used with" - " @runtime protocols") - if not _is_callable_members_only(cls): - if sys._getframe(2).f_globals['__name__'] in ['abc', 'functools']: - return NotImplemented - raise TypeError("Protocols with non-method members" - " don't support issubclass()") - if not isinstance(other, type): - # Same error as for issubclass(1, int) - raise TypeError('issubclass() arg 1 must be a class') - for attr in _get_protocol_attrs(cls): - for base in other.__mro__: - if attr in base.__dict__: - if base.__dict__[attr] is None: - return NotImplemented - break - annotations = getattr(base, '__annotations__', {}) - if (isinstance(annotations, typing.Mapping) and - attr in annotations and - isinstance(other, _ProtocolMeta) and - other._is_protocol): - break - else: - return NotImplemented - return True - if '__subclasshook__' not in cls.__dict__: - cls.__subclasshook__ = _proto_hook + class Movie(TypedDict, total=False): + title: Required[str] + year: int - # We have nothing more to do for non-protocols. - if not cls._is_protocol: - return + m = Movie( + title='The Matrix', # typechecker error if key is omitted + year=1999, + ) - # Check consistency of bases. - for base in cls.__bases__: - if not (base in (object, Generic) or - base.__module__ == 'collections.abc' and - base.__name__ in _PROTO_WHITELIST or - isinstance(base, _ProtocolMeta) and base._is_protocol): - raise TypeError('Protocols can only inherit from other' - ' protocols, got %r' % base) + There is no runtime checking that a required key is actually provided + when instantiating a related TypedDict. + """) + NotRequired = _RequiredForm( + 'NotRequired', + doc="""A special typing construct to mark a key of a TypedDict as + potentially missing. For example: + + class Movie(TypedDict): + title: str + year: NotRequired[int] + + m = Movie( + title='The Matrix', # typechecker error if key is omitted + year=1999, + ) + """) - def _no_init(self, *args, **kwargs): - if type(self)._is_protocol: - raise TypeError('Protocols cannot be instantiated') - cls.__init__ = _no_init +_UNPACK_DOC = """\ +Type unpack operator. -if hasattr(typing, 'runtime_checkable'): - runtime_checkable = typing.runtime_checkable -elif HAVE_PROTOCOLS: - def runtime_checkable(cls): - """Mark a protocol class as a runtime protocol, so that it - can be used with isinstance() and issubclass(). Raise TypeError - if applied to a non-protocol class. +The type unpack operator takes the child types from some container type, +such as `tuple[int, str]` or a `TypeVarTuple`, and 'pulls them out'. For +example: - This allows a simple-minded structural check very similar to the - one-offs in collections.abc such as Hashable. - """ - if not isinstance(cls, _ProtocolMeta) or not cls._is_protocol: - raise TypeError('@runtime_checkable can be only applied to protocol classes,' - ' got %r' % cls) - cls._is_runtime_protocol = True - return cls + # For some generic class `Foo`: + Foo[Unpack[tuple[int, str]]] # Equivalent to Foo[int, str] + Ts = TypeVarTuple('Ts') + # Specifies that `Bar` is generic in an arbitrary number of types. + # (Think of `Ts` as a tuple of an arbitrary number of individual + # `TypeVar`s, which the `Unpack` is 'pulling out' directly into the + # `Generic[]`.) + class Bar(Generic[Unpack[Ts]]): ... + Bar[int] # Valid + Bar[int, str] # Also valid -if HAVE_PROTOCOLS: - # Exists for backwards compatibility. - runtime = runtime_checkable +From Python 3.11, this can also be done using the `*` operator: + Foo[*tuple[int, str]] + class Bar(Generic[*Ts]): ... -if hasattr(typing, 'SupportsIndex'): - SupportsIndex = typing.SupportsIndex -elif HAVE_PROTOCOLS: - @runtime_checkable - class SupportsIndex(Protocol): - __slots__ = () +The operator can also be used along with a `TypedDict` to annotate +`**kwargs` in a function signature. For instance: - @abc.abstractmethod - def __index__(self) -> int: - pass + class Movie(TypedDict): + name: str + year: int + # This function expects two keyword arguments - *name* of type `str` and + # *year* of type `int`. + def foo(**kwargs: Unpack[Movie]): ... -if sys.version_info[:2] >= (3, 9): - # The standard library TypedDict in Python 3.8 does not store runtime information - # about which (if any) keys are optional. See https://bugs.python.org/issue38834 - TypedDict = typing.TypedDict -else: - def _check_fails(cls, other): - try: - if sys._getframe(1).f_globals['__name__'] not in ['abc', - 'functools', - 'typing']: - # Typed dicts are only for static structural subtyping. - raise TypeError('TypedDict does not support instance and class checks') - except (AttributeError, ValueError): - pass - return False - - def _dict_new(*args, **kwargs): - if not args: - raise TypeError('TypedDict.__new__(): not enough arguments') - _, args = args[0], args[1:] # allow the "cls" keyword be passed - return dict(*args, **kwargs) - - _dict_new.__text_signature__ = '($cls, _typename, _fields=None, /, **kwargs)' - - def _typeddict_new(*args, total=True, **kwargs): - if not args: - raise TypeError('TypedDict.__new__(): not enough arguments') - _, args = args[0], args[1:] # allow the "cls" keyword be passed - if args: - typename, args = args[0], args[1:] # allow the "_typename" keyword be passed - elif '_typename' in kwargs: - typename = kwargs.pop('_typename') - import warnings - warnings.warn("Passing '_typename' as keyword argument is deprecated", - DeprecationWarning, stacklevel=2) - else: - raise TypeError("TypedDict.__new__() missing 1 required positional " - "argument: '_typename'") - if args: - try: - fields, = args # allow the "_fields" keyword be passed - except ValueError: - raise TypeError('TypedDict.__new__() takes from 2 to 3 ' - 'positional arguments but {} ' - 'were given'.format(len(args) + 2)) - elif '_fields' in kwargs and len(kwargs) == 1: - fields = kwargs.pop('_fields') - import warnings - warnings.warn("Passing '_fields' as keyword argument is deprecated", - DeprecationWarning, stacklevel=2) - else: - fields = None +Note that there is only some runtime checking of this operator. Not +everything the runtime allows may be accepted by static type checkers. - if fields is None: - fields = kwargs - elif kwargs: - raise TypeError("TypedDict takes either a dict or keyword arguments," - " but not both") +For more information, see PEP 646 and PEP 692. +""" - ns = {'__annotations__': dict(fields), '__total__': total} - try: - # Setting correct module is necessary to make typed dict classes pickleable. - ns['__module__'] = sys._getframe(1).f_globals.get('__name__', '__main__') - except (AttributeError, ValueError): - pass - return _TypedDictMeta(typename, (), ns) +if sys.version_info >= (3, 12): # PEP 692 changed the repr of Unpack[] + Unpack = typing.Unpack - _typeddict_new.__text_signature__ = ('($cls, _typename, _fields=None,' - ' /, *, total=True, **kwargs)') + def _is_unpack(obj): + return get_origin(obj) is Unpack - class _TypedDictMeta(type): - def __new__(cls, name, bases, ns, total=True): - # Create new typed dict class object. - # This method is called directly when TypedDict is subclassed, - # or via _typeddict_new when TypedDict is instantiated. This way - # TypedDict supports all three syntaxes described in its docstring. - # Subclasses and instances of TypedDict return actual dictionaries - # via _dict_new. - ns['__new__'] = _typeddict_new if name == 'TypedDict' else _dict_new - tp_dict = super(_TypedDictMeta, cls).__new__(cls, name, (dict,), ns) +elif sys.version_info[:2] >= (3, 9): + class _UnpackSpecialForm(_ExtensionsSpecialForm, _root=True): + def __init__(self, getitem): + super().__init__(getitem) + self.__doc__ = _UNPACK_DOC - annotations = {} - own_annotations = ns.get('__annotations__', {}) - own_annotation_keys = set(own_annotations.keys()) - msg = "TypedDict('Name', {f0: t0, f1: t1, ...}); each t must be a type" - own_annotations = { - n: typing._type_check(tp, msg) for n, tp in own_annotations.items() - } - required_keys = set() - optional_keys = set() + class _UnpackAlias(typing._GenericAlias, _root=True): + __class__ = typing.TypeVar - for base in bases: - annotations.update(base.__dict__.get('__annotations__', {})) - required_keys.update(base.__dict__.get('__required_keys__', ())) - optional_keys.update(base.__dict__.get('__optional_keys__', ())) + @_UnpackSpecialForm + def Unpack(self, parameters): + item = typing._type_check(parameters, f'{self._name} accepts only a single type.') + return _UnpackAlias(self, (item,)) - annotations.update(own_annotations) - if total: - required_keys.update(own_annotation_keys) - else: - optional_keys.update(own_annotation_keys) + def _is_unpack(obj): + return isinstance(obj, _UnpackAlias) - tp_dict.__annotations__ = annotations - tp_dict.__required_keys__ = frozenset(required_keys) - tp_dict.__optional_keys__ = frozenset(optional_keys) - if not hasattr(tp_dict, '__total__'): - tp_dict.__total__ = total - return tp_dict +else: + class _UnpackAlias(typing._GenericAlias, _root=True): + __class__ = typing.TypeVar + + class _UnpackForm(_ExtensionsSpecialForm, _root=True): + def __getitem__(self, parameters): + item = typing._type_check(parameters, + f'{self._name} accepts only a single type.') + return _UnpackAlias(self, (item,)) - __instancecheck__ = __subclasscheck__ = _check_fails + Unpack = _UnpackForm('Unpack', doc=_UNPACK_DOC) - TypedDict = _TypedDictMeta('TypedDict', (dict,), {}) - TypedDict.__module__ = __name__ - TypedDict.__doc__ = \ - """A simple typed name space. At runtime it is equivalent to a plain dict. + def _is_unpack(obj): + return isinstance(obj, _UnpackAlias) + + +if hasattr(typing, "TypeVarTuple"): # 3.11+ + + # Add default parameter - PEP 696 + class TypeVarTuple(metaclass=_TypeVarLikeMeta): + """Type variable tuple.""" + + _backported_typevarlike = typing.TypeVarTuple + + def __new__(cls, name, *, default=_marker): + tvt = typing.TypeVarTuple(name) + _set_default(tvt, default) + _set_module(tvt) + return tvt + + def __init_subclass__(self, *args, **kwds): + raise TypeError("Cannot subclass special typing classes") + +else: + class TypeVarTuple(_DefaultMixin): + """Type variable tuple. - TypedDict creates a dictionary type that expects all of its - instances to have a certain set of keys, with each key - associated with a value of a consistent type. This expectation - is not checked at runtime but is only enforced by type checkers. Usage:: - class Point2D(TypedDict): - x: int - y: int - label: str + Ts = TypeVarTuple('Ts') - a: Point2D = {'x': 1, 'y': 2, 'label': 'good'} # OK - b: Point2D = {'z': 3, 'label': 'bad'} # Fails type check + In the same way that a normal type variable is a stand-in for a single + type such as ``int``, a type variable *tuple* is a stand-in for a *tuple* + type such as ``Tuple[int, str]``. - assert Point2D(x=1, y=2, label='first') == dict(x=1, y=2, label='first') + Type variable tuples can be used in ``Generic`` declarations. + Consider the following example:: - The type info can be accessed via the Point2D.__annotations__ dict, and - the Point2D.__required_keys__ and Point2D.__optional_keys__ frozensets. - TypedDict supports two additional equivalent forms:: + class Array(Generic[*Ts]): ... - Point2D = TypedDict('Point2D', x=int, y=int, label=str) - Point2D = TypedDict('Point2D', {'x': int, 'y': int, 'label': str}) + The ``Ts`` type variable tuple here behaves like ``tuple[T1, T2]``, + where ``T1`` and ``T2`` are type variables. To use these type variables + as type parameters of ``Array``, we must *unpack* the type variable tuple using + the star operator: ``*Ts``. The signature of ``Array`` then behaves + as if we had simply written ``class Array(Generic[T1, T2]): ...``. + In contrast to ``Generic[T1, T2]``, however, ``Generic[*Shape]`` allows + us to parameterise the class with an *arbitrary* number of type parameters. - The class syntax is only supported in Python 3.6+, while two other - syntax forms work for Python 2.7 and 3.2+ - """ + Type variable tuples can be used anywhere a normal ``TypeVar`` can. + This includes class definitions, as shown above, as well as function + signatures and variable annotations:: + class Array(Generic[*Ts]): -# Python 3.9+ has PEP 593 (Annotated and modified get_type_hints) -if hasattr(typing, 'Annotated'): - Annotated = typing.Annotated - get_type_hints = typing.get_type_hints - # Not exported and not a public API, but needed for get_origin() and get_args() - # to work. - _AnnotatedAlias = typing._AnnotatedAlias -elif PEP_560: - class _AnnotatedAlias(typing._GenericAlias, _root=True): - """Runtime representation of an annotated type. + def __init__(self, shape: Tuple[*Ts]): + self._shape: Tuple[*Ts] = shape + + def get_shape(self) -> Tuple[*Ts]: + return self._shape + + shape = (Height(480), Width(640)) + x: Array[Height, Width] = Array(shape) + y = abs(x) # Inferred type is Array[Height, Width] + z = x + x # ... is Array[Height, Width] + x.get_shape() # ... is tuple[Height, Width] - At its core 'Annotated[t, dec1, dec2, ...]' is an alias for the type 't' - with extra annotations. The alias behaves like a normal typing alias, - instantiating is the same as instantiating the underlying type, binding - it to types is also the same. """ - def __init__(self, origin, metadata): - if isinstance(origin, _AnnotatedAlias): - metadata = origin.__metadata__ + metadata - origin = origin.__origin__ - super().__init__(origin, origin) - self.__metadata__ = metadata - def copy_with(self, params): - assert len(params) == 1 - new_type = params[0] - return _AnnotatedAlias(new_type, self.__metadata__) + # Trick Generic __parameters__. + __class__ = typing.TypeVar - def __repr__(self): - return "typing_extensions.Annotated[{}, {}]".format( - typing._type_repr(self.__origin__), - ", ".join(repr(a) for a in self.__metadata__) - ) + def __iter__(self): + yield self.__unpacked__ - def __reduce__(self): - return operator.getitem, ( - Annotated, (self.__origin__,) + self.__metadata__ - ) + def __init__(self, name, *, default=_marker): + self.__name__ = name + _DefaultMixin.__init__(self, default) - def __eq__(self, other): - if not isinstance(other, _AnnotatedAlias): - return NotImplemented - if self.__origin__ != other.__origin__: - return False - return self.__metadata__ == other.__metadata__ + # for pickling: + def_mod = _caller() + if def_mod != 'typing_extensions': + self.__module__ = def_mod + + self.__unpacked__ = Unpack[self] + + def __repr__(self): + return self.__name__ def __hash__(self): - return hash((self.__origin__, self.__metadata__)) - - class Annotated: - """Add context specific metadata to a type. + return object.__hash__(self) - Example: Annotated[int, runtime_check.Unsigned] indicates to the - hypothetical runtime_check module that this type is an unsigned int. - Every other consumer of this type can ignore this metadata and treat - this type as int. + def __eq__(self, other): + return self is other - The first argument to Annotated must be a valid type (and will be in - the __origin__ field), the remaining arguments are kept as a tuple in - the __extra__ field. + def __reduce__(self): + return self.__name__ - Details: + def __init_subclass__(self, *args, **kwds): + if '_root' not in kwds: + raise TypeError("Cannot subclass special typing classes") - - It's an error to call `Annotated` with less than two arguments. - - Nested Annotated are flattened:: - Annotated[Annotated[T, Ann1, Ann2], Ann3] == Annotated[T, Ann1, Ann2, Ann3] +if hasattr(typing, "reveal_type"): + reveal_type = typing.reveal_type +else: + def reveal_type(__obj: T) -> T: + """Reveal the inferred type of a variable. - - Instantiating an annotated type is equivalent to instantiating the - underlying type:: + When a static type checker encounters a call to ``reveal_type()``, + it will emit the inferred type of the argument:: - Annotated[C, Ann1](5) == C(5) + x: int = 1 + reveal_type(x) - - Annotated can be used as a generic type alias:: + Running a static type checker (e.g., ``mypy``) on this example + will produce output similar to 'Revealed type is "builtins.int"'. - Optimized = Annotated[T, runtime.Optimize()] - Optimized[int] == Annotated[int, runtime.Optimize()] + At runtime, the function prints the runtime type of the + argument and returns it unchanged. - OptimizedList = Annotated[List[T], runtime.Optimize()] - OptimizedList[int] == Annotated[List[int], runtime.Optimize()] """ + print(f"Runtime type is {type(__obj).__name__!r}", file=sys.stderr) + return __obj - __slots__ = () - def __new__(cls, *args, **kwargs): - raise TypeError("Type Annotated cannot be instantiated.") +if hasattr(typing, "assert_never"): + assert_never = typing.assert_never +else: + def assert_never(__arg: Never) -> Never: + """Assert to the type checker that a line of code is unreachable. - @_tp_cache - def __class_getitem__(cls, params): - if not isinstance(params, tuple) or len(params) < 2: - raise TypeError("Annotated[...] should be used " - "with at least two arguments (a type and an " - "annotation).") - msg = "Annotated[t, ...]: t must be a type." - origin = typing._type_check(params[0], msg) - metadata = tuple(params[1:]) - return _AnnotatedAlias(origin, metadata) + Example:: - def __init_subclass__(cls, *args, **kwargs): - raise TypeError( - "Cannot subclass {}.Annotated".format(cls.__module__) - ) + def int_or_str(arg: int | str) -> None: + match arg: + case int(): + print("It's an int") + case str(): + print("It's a str") + case _: + assert_never(arg) + + If a type checker finds that a call to assert_never() is + reachable, it will emit an error. + + At runtime, this throws an exception when called. - def _strip_annotations(t): - """Strips the annotations from a given type. """ - if isinstance(t, _AnnotatedAlias): - return _strip_annotations(t.__origin__) - if isinstance(t, typing._GenericAlias): - stripped_args = tuple(_strip_annotations(a) for a in t.__args__) - if stripped_args == t.__args__: - return t - res = t.copy_with(stripped_args) - res._special = t._special - return res - return t + raise AssertionError("Expected code to be unreachable") - def get_type_hints(obj, globalns=None, localns=None, include_extras=False): - """Return type hints for an object. - This is often the same as obj.__annotations__, but it handles - forward references encoded as string literals, adds Optional[t] if a - default value equal to None is set and recursively replaces all - 'Annotated[T, ...]' with 'T' (unless 'include_extras=True'). +if sys.version_info >= (3, 12): + # dataclass_transform exists in 3.11 but lacks the frozen_default parameter + dataclass_transform = typing.dataclass_transform +else: + def dataclass_transform( + *, + eq_default: bool = True, + order_default: bool = False, + kw_only_default: bool = False, + frozen_default: bool = False, + field_specifiers: typing.Tuple[ + typing.Union[typing.Type[typing.Any], typing.Callable[..., typing.Any]], + ... + ] = (), + **kwargs: typing.Any, + ) -> typing.Callable[[T], T]: + """Decorator that marks a function, class, or metaclass as providing + dataclass-like behavior. + + Example: + + from typing_extensions import dataclass_transform + + _T = TypeVar("_T") + + # Used on a decorator function + @dataclass_transform() + def create_model(cls: type[_T]) -> type[_T]: + ... + return cls - The argument may be a module, class, method, or function. The annotations - are returned as a dictionary. For classes, annotations include also - inherited members. + @create_model + class CustomerModel: + id: int + name: str - TypeError is raised if the argument is not of a type that can contain - annotations, and an empty dictionary is returned if no annotations are - present. + # Used on a base class + @dataclass_transform() + class ModelBase: ... - BEWARE -- the behavior of globalns and localns is counterintuitive - (unless you are familiar with how eval() and exec() work). The - search order is locals first, then globals. + class CustomerModel(ModelBase): + id: int + name: str - - If no dict arguments are passed, an attempt is made to use the - globals from obj (or the respective module's globals for classes), - and these are also used as the locals. If the object does not appear - to have globals, an empty dictionary is used. + # Used on a metaclass + @dataclass_transform() + class ModelMeta(type): ... - - If one dict argument is passed, it is used for both globals and - locals. + class ModelBase(metaclass=ModelMeta): ... + + class CustomerModel(ModelBase): + id: int + name: str + + Each of the ``CustomerModel`` classes defined in this example will now + behave similarly to a dataclass created with the ``@dataclasses.dataclass`` + decorator. For example, the type checker will synthesize an ``__init__`` + method. + + The arguments to this decorator can be used to customize this behavior: + - ``eq_default`` indicates whether the ``eq`` parameter is assumed to be + True or False if it is omitted by the caller. + - ``order_default`` indicates whether the ``order`` parameter is + assumed to be True or False if it is omitted by the caller. + - ``kw_only_default`` indicates whether the ``kw_only`` parameter is + assumed to be True or False if it is omitted by the caller. + - ``frozen_default`` indicates whether the ``frozen`` parameter is + assumed to be True or False if it is omitted by the caller. + - ``field_specifiers`` specifies a static list of supported classes + or functions that describe fields, similar to ``dataclasses.field()``. + + At runtime, this decorator records its arguments in the + ``__dataclass_transform__`` attribute on the decorated object. + + See PEP 681 for details. - - If two dict arguments are passed, they specify globals and - locals, respectively. """ - hint = typing.get_type_hints(obj, globalns=globalns, localns=localns) - if include_extras: - return hint - return {k: _strip_annotations(t) for k, t in hint.items()} + def decorator(cls_or_fn): + cls_or_fn.__dataclass_transform__ = { + "eq_default": eq_default, + "order_default": order_default, + "kw_only_default": kw_only_default, + "frozen_default": frozen_default, + "field_specifiers": field_specifiers, + "kwargs": kwargs, + } + return cls_or_fn + return decorator -elif HAVE_ANNOTATED: - def _is_dunder(name): - """Returns True if name is a __dunder_variable_name__.""" - return len(name) > 4 and name.startswith('__') and name.endswith('__') +if hasattr(typing, "override"): + override = typing.override +else: + _F = typing.TypeVar("_F", bound=typing.Callable[..., typing.Any]) - # Prior to Python 3.7 types did not have `copy_with`. A lot of the equality - # checks, argument expansion etc. are done on the _subs_tre. As a result we - # can't provide a get_type_hints function that strips out annotations. + def override(__arg: _F) -> _F: + """Indicate that a method is intended to override a method in a base class. - class AnnotatedMeta(typing.GenericMeta): - """Metaclass for Annotated""" + Usage: - def __new__(cls, name, bases, namespace, **kwargs): - if any(b is not object for b in bases): - raise TypeError("Cannot subclass " + str(Annotated)) - return super().__new__(cls, name, bases, namespace, **kwargs) + class Base: + def method(self) -> None: ... + pass - @property - def __metadata__(self): - return self._subs_tree()[2] + class Child(Base): + @override + def method(self) -> None: + super().method() - def _tree_repr(self, tree): - cls, origin, metadata = tree - if not isinstance(origin, tuple): - tp_repr = typing._type_repr(origin) - else: - tp_repr = origin[0]._tree_repr(origin) - metadata_reprs = ", ".join(repr(arg) for arg in metadata) - return '%s[%s, %s]' % (cls, tp_repr, metadata_reprs) - - def _subs_tree(self, tvars=None, args=None): # noqa - if self is Annotated: - return Annotated - res = super()._subs_tree(tvars=tvars, args=args) - # Flatten nested Annotated - if isinstance(res[1], tuple) and res[1][0] is Annotated: - sub_tp = res[1][1] - sub_annot = res[1][2] - return (Annotated, sub_tp, sub_annot + res[2]) - return res + When this decorator is applied to a method, the type checker will + validate that it overrides a method with the same name on a base class. + This helps prevent bugs that may occur when a base class is changed + without an equivalent change to a child class. - def _get_cons(self): - """Return the class used to create instance of this type.""" - if self.__origin__ is None: - raise TypeError("Cannot get the underlying type of a " - "non-specialized Annotated type.") - tree = self._subs_tree() - while isinstance(tree, tuple) and tree[0] is Annotated: - tree = tree[1] - if isinstance(tree, tuple): - return tree[0] - else: - return tree - - @_tp_cache - def __getitem__(self, params): - if not isinstance(params, tuple): - params = (params,) - if self.__origin__ is not None: # specializing an instantiated type - return super().__getitem__(params) - elif not isinstance(params, tuple) or len(params) < 2: - raise TypeError("Annotated[...] should be instantiated " - "with at least two arguments (a type and an " - "annotation).") - else: - msg = "Annotated[t, ...]: t must be a type." - tp = typing._type_check(params[0], msg) - metadata = tuple(params[1:]) - return self.__class__( - self.__name__, - self.__bases__, - _no_slots_copy(self.__dict__), - tvars=_type_vars((tp,)), - # Metadata is a tuple so it won't be touched by _replace_args et al. - args=(tp, metadata), - origin=self, - ) + There is no runtime checking of these properties. The decorator + sets the ``__override__`` attribute to ``True`` on the decorated object + to allow runtime introspection. - def __call__(self, *args, **kwargs): - cons = self._get_cons() - result = cons(*args, **kwargs) - try: - result.__orig_class__ = self - except AttributeError: - pass - return result - - def __getattr__(self, attr): - # For simplicity we just don't relay all dunder names - if self.__origin__ is not None and not _is_dunder(attr): - return getattr(self._get_cons(), attr) - raise AttributeError(attr) - - def __setattr__(self, attr, value): - if _is_dunder(attr) or attr.startswith('_abc_'): - super().__setattr__(attr, value) - elif self.__origin__ is None: - raise AttributeError(attr) - else: - setattr(self._get_cons(), attr, value) + See PEP 698 for details. - def __instancecheck__(self, obj): - raise TypeError("Annotated cannot be used with isinstance().") + """ + try: + __arg.__override__ = True + except (AttributeError, TypeError): + # Skip the attribute silently if it is not writable. + # AttributeError happens if the object has __slots__ or a + # read-only property, TypeError if it's a builtin class. + pass + return __arg - def __subclasscheck__(self, cls): - raise TypeError("Annotated cannot be used with issubclass().") - class Annotated(metaclass=AnnotatedMeta): - """Add context specific metadata to a type. +if hasattr(typing, "deprecated"): + deprecated = typing.deprecated +else: + _T = typing.TypeVar("_T") - Example: Annotated[int, runtime_check.Unsigned] indicates to the - hypothetical runtime_check module that this type is an unsigned int. - Every other consumer of this type can ignore this metadata and treat - this type as int. + def deprecated( + __msg: str, + *, + category: typing.Optional[typing.Type[Warning]] = DeprecationWarning, + stacklevel: int = 1, + ) -> typing.Callable[[_T], _T]: + """Indicate that a class, function or overload is deprecated. - The first argument to Annotated must be a valid type, the remaining - arguments are kept as a tuple in the __metadata__ field. + Usage: - Details: + @deprecated("Use B instead") + class A: + pass - - It's an error to call `Annotated` with less than two arguments. - - Nested Annotated are flattened:: + @deprecated("Use g instead") + def f(): + pass - Annotated[Annotated[T, Ann1, Ann2], Ann3] == Annotated[T, Ann1, Ann2, Ann3] + @overload + @deprecated("int support is deprecated") + def g(x: int) -> int: ... + @overload + def g(x: str) -> int: ... - - Instantiating an annotated type is equivalent to instantiating the - underlying type:: + When this decorator is applied to an object, the type checker + will generate a diagnostic on usage of the deprecated object. - Annotated[C, Ann1](5) == C(5) + The warning specified by ``category`` will be emitted on use + of deprecated objects. For functions, that happens on calls; + for classes, on instantiation. If the ``category`` is ``None``, + no warning is emitted. The ``stacklevel`` determines where the + warning is emitted. If it is ``1`` (the default), the warning + is emitted at the direct caller of the deprecated object; if it + is higher, it is emitted further up the stack. - - Annotated can be used as a generic type alias:: + The decorator sets the ``__deprecated__`` + attribute on the decorated object to the deprecation message + passed to the decorator. If applied to an overload, the decorator + must be after the ``@overload`` decorator for the attribute to + exist on the overload as returned by ``get_overloads()``. - Optimized = Annotated[T, runtime.Optimize()] - Optimized[int] == Annotated[int, runtime.Optimize()] + See PEP 702 for details. - OptimizedList = Annotated[List[T], runtime.Optimize()] - OptimizedList[int] == Annotated[List[int], runtime.Optimize()] """ + def decorator(__arg: _T) -> _T: + if category is None: + __arg.__deprecated__ = __msg + return __arg + elif isinstance(__arg, type): + original_new = __arg.__new__ + has_init = __arg.__init__ is not object.__init__ + + @functools.wraps(original_new) + def __new__(cls, *args, **kwargs): + warnings.warn(__msg, category=category, stacklevel=stacklevel + 1) + if original_new is not object.__new__: + return original_new(cls, *args, **kwargs) + # Mirrors a similar check in object.__new__. + elif not has_init and (args or kwargs): + raise TypeError(f"{cls.__name__}() takes no arguments") + else: + return original_new(cls) + + __arg.__new__ = staticmethod(__new__) + __arg.__deprecated__ = __new__.__deprecated__ = __msg + return __arg + elif callable(__arg): + @functools.wraps(__arg) + def wrapper(*args, **kwargs): + warnings.warn(__msg, category=category, stacklevel=stacklevel + 1) + return __arg(*args, **kwargs) + + __arg.__deprecated__ = wrapper.__deprecated__ = __msg + return wrapper + else: + raise TypeError( + "@deprecated decorator with non-None category must be applied to " + f"a class or callable, not {__arg!r}" + ) + + return decorator + + +# We have to do some monkey patching to deal with the dual nature of +# Unpack/TypeVarTuple: +# - We want Unpack to be a kind of TypeVar so it gets accepted in +# Generic[Unpack[Ts]] +# - We want it to *not* be treated as a TypeVar for the purposes of +# counting generic parameters, so that when we subscript a generic, +# the runtime doesn't try to substitute the Unpack with the subscripted type. +if not hasattr(typing, "TypeVarTuple"): + typing._collect_type_vars = _collect_type_vars + typing._check_generic = _check_generic + + +# Backport typing.NamedTuple as it exists in Python 3.12. +# In 3.11, the ability to define generic `NamedTuple`s was supported. +# This was explicitly disallowed in 3.9-3.10, and only half-worked in <=3.8. +# On 3.12, we added __orig_bases__ to call-based NamedTuples +# On 3.13, we deprecated kwargs-based NamedTuples +if sys.version_info >= (3, 13): + NamedTuple = typing.NamedTuple +else: + def _make_nmtuple(name, types, module, defaults=()): + fields = [n for n, t in types] + annotations = {n: typing._type_check(t, f"field {n} annotation must be a type") + for n, t in types} + nm_tpl = collections.namedtuple(name, fields, + defaults=defaults, module=module) + nm_tpl.__annotations__ = nm_tpl.__new__.__annotations__ = annotations + # The `_field_types` attribute was removed in 3.9; + # in earlier versions, it is the same as the `__annotations__` attribute + if sys.version_info < (3, 9): + nm_tpl._field_types = annotations + return nm_tpl + + _prohibited_namedtuple_fields = typing._prohibited + _special_namedtuple_fields = frozenset({'__module__', '__name__', '__annotations__'}) + + class _NamedTupleMeta(type): + def __new__(cls, typename, bases, ns): + assert _NamedTuple in bases + for base in bases: + if base is not _NamedTuple and base is not typing.Generic: + raise TypeError( + 'can only inherit from a NamedTuple type and Generic') + bases = tuple(tuple if base is _NamedTuple else base for base in bases) + types = ns.get('__annotations__', {}) + default_names = [] + for field_name in types: + if field_name in ns: + default_names.append(field_name) + elif default_names: + raise TypeError(f"Non-default namedtuple field {field_name} " + f"cannot follow default field" + f"{'s' if len(default_names) > 1 else ''} " + f"{', '.join(default_names)}") + nm_tpl = _make_nmtuple( + typename, types.items(), + defaults=[ns[n] for n in default_names], + module=ns['__module__'] + ) + nm_tpl.__bases__ = bases + if typing.Generic in bases: + if hasattr(typing, '_generic_class_getitem'): # 3.12+ + nm_tpl.__class_getitem__ = classmethod(typing._generic_class_getitem) + else: + class_getitem = typing.Generic.__class_getitem__.__func__ + nm_tpl.__class_getitem__ = classmethod(class_getitem) + # update from user namespace without overriding special namedtuple attributes + for key in ns: + if key in _prohibited_namedtuple_fields: + raise AttributeError("Cannot overwrite NamedTuple attribute " + key) + elif key not in _special_namedtuple_fields and key not in nm_tpl._fields: + setattr(nm_tpl, key, ns[key]) + if typing.Generic in bases: + nm_tpl.__init_subclass__() + return nm_tpl + + _NamedTuple = type.__new__(_NamedTupleMeta, 'NamedTuple', (), {}) + + def _namedtuple_mro_entries(bases): + assert NamedTuple in bases + return (_NamedTuple,) + + @_ensure_subclassable(_namedtuple_mro_entries) + def NamedTuple(__typename, __fields=_marker, **kwargs): + """Typed version of namedtuple. -# Python 3.8 has get_origin() and get_args() but those implementations aren't -# Annotated-aware, so we can't use those, only Python 3.9 versions will do. -if sys.version_info[:2] >= (3, 9): - get_origin = typing.get_origin - get_args = typing.get_args -elif PEP_560: - from typing import _GenericAlias # noqa + Usage:: - def get_origin(tp): - """Get the unsubscripted version of a type. + class Employee(NamedTuple): + name: str + id: int - This supports generic types, Callable, Tuple, Union, Literal, Final, ClassVar - and Annotated. Return None for unsupported types. Examples:: + This is equivalent to:: - get_origin(Literal[42]) is Literal - get_origin(int) is None - get_origin(ClassVar[int]) is ClassVar - get_origin(Generic) is Generic - get_origin(Generic[T]) is Generic - get_origin(Union[T, int]) is Union - get_origin(List[Tuple[T, T]][int]) == list + Employee = collections.namedtuple('Employee', ['name', 'id']) + + The resulting class has an extra __annotations__ attribute, giving a + dict that maps field names to types. (The field names are also in + the _fields attribute, which is part of the namedtuple API.) + An alternative equivalent functional syntax is also accepted:: + + Employee = NamedTuple('Employee', [('name', str), ('id', int)]) """ - if isinstance(tp, _AnnotatedAlias): - return Annotated - if isinstance(tp, _GenericAlias): - return tp.__origin__ - if tp is Generic: - return Generic - return None + if __fields is _marker: + if kwargs: + deprecated_thing = "Creating NamedTuple classes using keyword arguments" + deprecation_msg = ( + "{name} is deprecated and will be disallowed in Python {remove}. " + "Use the class-based or functional syntax instead." + ) + else: + deprecated_thing = "Failing to pass a value for the 'fields' parameter" + example = f"`{__typename} = NamedTuple({__typename!r}, [])`" + deprecation_msg = ( + "{name} is deprecated and will be disallowed in Python {remove}. " + "To create a NamedTuple class with 0 fields " + "using the functional syntax, " + "pass an empty list, e.g. " + ) + example + "." + elif __fields is None: + if kwargs: + raise TypeError( + "Cannot pass `None` as the 'fields' parameter " + "and also specify fields using keyword arguments" + ) + else: + deprecated_thing = "Passing `None` as the 'fields' parameter" + example = f"`{__typename} = NamedTuple({__typename!r}, [])`" + deprecation_msg = ( + "{name} is deprecated and will be disallowed in Python {remove}. " + "To create a NamedTuple class with 0 fields " + "using the functional syntax, " + "pass an empty list, e.g. " + ) + example + "." + elif kwargs: + raise TypeError("Either list of fields or keywords" + " can be provided to NamedTuple, not both") + if __fields is _marker or __fields is None: + warnings.warn( + deprecation_msg.format(name=deprecated_thing, remove="3.15"), + DeprecationWarning, + stacklevel=2, + ) + __fields = kwargs.items() + nt = _make_nmtuple(__typename, __fields, module=_caller()) + nt.__orig_bases__ = (NamedTuple,) + return nt + + # On 3.8+, alter the signature so that it matches typing.NamedTuple. + # The signature of typing.NamedTuple on >=3.8 is invalid syntax in Python 3.7, + # so just leave the signature as it is on 3.7. + if sys.version_info >= (3, 8): + _new_signature = '(typename, fields=None, /, **kwargs)' + if isinstance(NamedTuple, _types.FunctionType): + NamedTuple.__text_signature__ = _new_signature + else: + NamedTuple.__call__.__text_signature__ = _new_signature - def get_args(tp): - """Get type arguments with all substitutions performed. - For unions, basic simplifications used by Union constructor are performed. - Examples:: - get_args(Dict[str, int]) == (str, int) - get_args(int) == () - get_args(Union[int, Union[T, int], str][int]) == (int, str) - get_args(Union[int, Tuple[T, int]][str]) == (int, Tuple[str, int]) - get_args(Callable[[], T][int]) == ([], int) +if hasattr(collections.abc, "Buffer"): + Buffer = collections.abc.Buffer +else: + class Buffer(abc.ABC): + """Base class for classes that implement the buffer protocol. + + The buffer protocol allows Python objects to expose a low-level + memory buffer interface. Before Python 3.12, it is not possible + to implement the buffer protocol in pure Python code, or even + to check whether a class implements the buffer protocol. In + Python 3.12 and higher, the ``__buffer__`` method allows access + to the buffer protocol from Python code, and the + ``collections.abc.Buffer`` ABC allows checking whether a class + implements the buffer protocol. + + To indicate support for the buffer protocol in earlier versions, + inherit from this ABC, either in a stub file or at runtime, + or use ABC registration. This ABC provides no methods, because + there is no Python-accessible methods shared by pre-3.12 buffer + classes. It is useful primarily for static checks. + """ - if isinstance(tp, _AnnotatedAlias): - return (tp.__origin__,) + tp.__metadata__ - if isinstance(tp, _GenericAlias): - res = tp.__args__ - if get_origin(tp) is collections.abc.Callable and res[0] is not Ellipsis: - res = (list(res[:-1]), res[-1]) - return res - return () + # As a courtesy, register the most common stdlib buffer classes. + Buffer.register(memoryview) + Buffer.register(bytearray) + Buffer.register(bytes) -if hasattr(typing, 'TypeAlias'): - TypeAlias = typing.TypeAlias -elif sys.version_info[:2] >= (3, 9): - class _TypeAliasForm(typing._SpecialForm, _root=True): - def __repr__(self): - return 'typing_extensions.' + self._name - @_TypeAliasForm - def TypeAlias(self, parameters): - """Special marker indicating that an assignment should - be recognized as a proper type alias definition by type - checkers. +# Backport of types.get_original_bases, available on 3.12+ in CPython +if hasattr(_types, "get_original_bases"): + get_original_bases = _types.get_original_bases +else: + def get_original_bases(__cls): + """Return the class's "original" bases prior to modification by `__mro_entries__`. - For example:: + Examples:: - Predicate: TypeAlias = Callable[..., bool] + from typing import TypeVar, Generic + from typing_extensions import NamedTuple, TypedDict + + T = TypeVar("T") + class Foo(Generic[T]): ... + class Bar(Foo[int], float): ... + class Baz(list[str]): ... + Eggs = NamedTuple("Eggs", [("a", int), ("b", str)]) + Spam = TypedDict("Spam", {"a": int, "b": str}) + + assert get_original_bases(Bar) == (Foo[int], float) + assert get_original_bases(Baz) == (list[str],) + assert get_original_bases(Eggs) == (NamedTuple,) + assert get_original_bases(Spam) == (TypedDict,) + assert get_original_bases(int) == (object,) + """ + try: + return __cls.__orig_bases__ + except AttributeError: + try: + return __cls.__bases__ + except AttributeError: + raise TypeError( + f'Expected an instance of type, not {type(__cls).__name__!r}' + ) from None - It's invalid when used anywhere except as in the example above. + +# NewType is a class on Python 3.10+, making it pickleable +# The error message for subclassing instances of NewType was improved on 3.11+ +if sys.version_info >= (3, 11): + NewType = typing.NewType +else: + class NewType: + """NewType creates simple unique types with almost zero + runtime overhead. NewType(name, tp) is considered a subtype of tp + by static type checkers. At runtime, NewType(name, tp) returns + a dummy callable that simply returns its argument. Usage:: + UserId = NewType('UserId', int) + def name_by_id(user_id: UserId) -> str: + ... + UserId('user') # Fails type check + name_by_id(42) # Fails type check + name_by_id(UserId(42)) # OK + num = UserId(5) + 1 # type: int """ - raise TypeError("{} is not subscriptable".format(self)) -elif sys.version_info[:2] >= (3, 7): - class _TypeAliasForm(typing._SpecialForm, _root=True): + def __call__(self, obj): + return obj + + def __init__(self, name, tp): + self.__qualname__ = name + if '.' in name: + name = name.rpartition('.')[-1] + self.__name__ = name + self.__supertype__ = tp + def_mod = _caller() + if def_mod != 'typing_extensions': + self.__module__ = def_mod + + def __mro_entries__(self, bases): + # We defined __mro_entries__ to get a better error message + # if a user attempts to subclass a NewType instance. bpo-46170 + supercls_name = self.__name__ + + class Dummy: + def __init_subclass__(cls): + subcls_name = cls.__name__ + raise TypeError( + f"Cannot subclass an instance of NewType. " + f"Perhaps you were looking for: " + f"`{subcls_name} = NewType({subcls_name!r}, {supercls_name})`" + ) + + return (Dummy,) + def __repr__(self): - return 'typing_extensions.' + self._name + return f'{self.__module__}.{self.__qualname__}' - TypeAlias = _TypeAliasForm('TypeAlias', - doc="""Special marker indicating that an assignment should - be recognized as a proper type alias definition by type - checkers. + def __reduce__(self): + return self.__qualname__ - For example:: + if sys.version_info >= (3, 10): + # PEP 604 methods + # It doesn't make sense to have these methods on Python <3.10 - Predicate: TypeAlias = Callable[..., bool] + def __or__(self, other): + return typing.Union[self, other] - It's invalid when used anywhere except as in the example - above.""") + def __ror__(self, other): + return typing.Union[other, self] -elif hasattr(typing, '_FinalTypingBase'): - class _TypeAliasMeta(typing.TypingMeta): - """Metaclass for TypeAlias""" - def __repr__(self): - return 'typing_extensions.TypeAlias' +if hasattr(typing, "TypeAliasType"): + TypeAliasType = typing.TypeAliasType +else: + def _is_unionable(obj): + """Corresponds to is_unionable() in unionobject.c in CPython.""" + return obj is None or isinstance(obj, ( + type, + _types.GenericAlias, + _types.UnionType, + TypeAliasType, + )) - class _TypeAliasBase(typing._FinalTypingBase, metaclass=_TypeAliasMeta, _root=True): - """Special marker indicating that an assignment should - be recognized as a proper type alias definition by type - checkers. + class TypeAliasType: + """Create named, parameterized type aliases. - For example:: + This provides a backport of the new `type` statement in Python 3.12: - Predicate: TypeAlias = Callable[..., bool] + type ListOrSet[T] = list[T] | set[T] + + is equivalent to: + + T = TypeVar("T") + ListOrSet = TypeAliasType("ListOrSet", list[T] | set[T], type_params=(T,)) + + The name ListOrSet can then be used as an alias for the type it refers to. + + The type_params argument should contain all the type parameters used + in the value of the type alias. If the alias is not generic, this + argument is omitted. + + Static type checkers should only support type aliases declared using + TypeAliasType that follow these rules: + + - The first argument (the name) must be a string literal. + - The TypeAliasType instance must be immediately assigned to a variable + of the same name. (For example, 'X = TypeAliasType("Y", int)' is invalid, + as is 'X, Y = TypeAliasType("X", int), TypeAliasType("Y", int)'). - It's invalid when used anywhere except as in the example above. """ - __slots__ = () - def __instancecheck__(self, obj): - raise TypeError("TypeAlias cannot be used with isinstance().") + def __init__(self, name: str, value, *, type_params=()): + if not isinstance(name, str): + raise TypeError("TypeAliasType name must be a string") + self.__value__ = value + self.__type_params__ = type_params - def __subclasscheck__(self, cls): - raise TypeError("TypeAlias cannot be used with issubclass().") + parameters = [] + for type_param in type_params: + if isinstance(type_param, TypeVarTuple): + parameters.extend(type_param) + else: + parameters.append(type_param) + self.__parameters__ = tuple(parameters) + def_mod = _caller() + if def_mod != 'typing_extensions': + self.__module__ = def_mod + # Setting this attribute closes the TypeAliasType from further modification + self.__name__ = name + + def __setattr__(self, __name: str, __value: object) -> None: + if hasattr(self, "__name__"): + self._raise_attribute_error(__name) + super().__setattr__(__name, __value) + + def __delattr__(self, __name: str) -> Never: + self._raise_attribute_error(__name) + + def _raise_attribute_error(self, name: str) -> Never: + # Match the Python 3.12 error messages exactly + if name == "__name__": + raise AttributeError("readonly attribute") + elif name in {"__value__", "__type_params__", "__parameters__", "__module__"}: + raise AttributeError( + f"attribute '{name}' of 'typing.TypeAliasType' objects " + "is not writable" + ) + else: + raise AttributeError( + f"'typing.TypeAliasType' object has no attribute '{name}'" + ) - def __repr__(self): - return 'typing_extensions.TypeAlias' + def __repr__(self) -> str: + return self.__name__ - TypeAlias = _TypeAliasBase(_root=True) -else: - class _TypeAliasMeta(typing.TypingMeta): - """Metaclass for TypeAlias""" + def __getitem__(self, parameters): + if not isinstance(parameters, tuple): + parameters = (parameters,) + parameters = [ + typing._type_check( + item, f'Subscripting {self.__name__} requires a type.' + ) + for item in parameters + ] + return typing._GenericAlias(self, tuple(parameters)) - def __instancecheck__(self, obj): - raise TypeError("TypeAlias cannot be used with isinstance().") + def __reduce__(self): + return self.__name__ - def __subclasscheck__(self, cls): - raise TypeError("TypeAlias cannot be used with issubclass().") + def __init_subclass__(cls, *args, **kwargs): + raise TypeError( + "type 'typing_extensions.TypeAliasType' is not an acceptable base type" + ) - def __call__(self, *args, **kwargs): - raise TypeError("Cannot instantiate TypeAlias") + # The presence of this method convinces typing._type_check + # that TypeAliasTypes are types. + def __call__(self): + raise TypeError("Type alias is not callable") - class TypeAlias(metaclass=_TypeAliasMeta, _root=True): - """Special marker indicating that an assignment should - be recognized as a proper type alias definition by type - checkers. + if sys.version_info >= (3, 10): + def __or__(self, right): + # For forward compatibility with 3.12, reject Unions + # that are not accepted by the built-in Union. + if not _is_unionable(right): + return NotImplemented + return typing.Union[self, right] - For example:: + def __ror__(self, left): + if not _is_unionable(left): + return NotImplemented + return typing.Union[left, self] - Predicate: TypeAlias = Callable[..., bool] - It's invalid when used anywhere except as in the example above. +if hasattr(typing, "is_protocol"): + is_protocol = typing.is_protocol + get_protocol_members = typing.get_protocol_members +else: + def is_protocol(__tp: type) -> bool: + """Return True if the given type is a Protocol. + + Example:: + + >>> from typing_extensions import Protocol, is_protocol + >>> class P(Protocol): + ... def a(self) -> str: ... + ... b: int + >>> is_protocol(P) + True + >>> is_protocol(int) + False """ - __slots__ = () + return ( + isinstance(__tp, type) + and getattr(__tp, '_is_protocol', False) + and __tp is not Protocol + and __tp is not getattr(typing, "Protocol", object()) + ) + + def get_protocol_members(__tp: type) -> typing.FrozenSet[str]: + """Return the set of members defined in a Protocol. + + Example:: + + >>> from typing_extensions import Protocol, get_protocol_members + >>> class P(Protocol): + ... def a(self) -> str: ... + ... b: int + >>> get_protocol_members(P) + frozenset({'a', 'b'}) + + Raise a TypeError for arguments that are not Protocols. + """ + if not is_protocol(__tp): + raise TypeError(f'{__tp!r} is not a Protocol') + if hasattr(__tp, '__protocol_attrs__'): + return frozenset(__tp.__protocol_attrs__) + return frozenset(_get_protocol_attrs(__tp)) + + +# Aliases for items that have always been in typing. +# Explicitly assign these (rather than using `from typing import *` at the top), +# so that we get a CI error if one of these is deleted from typing.py +# in a future version of Python +AbstractSet = typing.AbstractSet +AnyStr = typing.AnyStr +BinaryIO = typing.BinaryIO +Callable = typing.Callable +Collection = typing.Collection +Container = typing.Container +Dict = typing.Dict +ForwardRef = typing.ForwardRef +FrozenSet = typing.FrozenSet +Generator = typing.Generator +Generic = typing.Generic +Hashable = typing.Hashable +IO = typing.IO +ItemsView = typing.ItemsView +Iterable = typing.Iterable +Iterator = typing.Iterator +KeysView = typing.KeysView +List = typing.List +Mapping = typing.Mapping +MappingView = typing.MappingView +Match = typing.Match +MutableMapping = typing.MutableMapping +MutableSequence = typing.MutableSequence +MutableSet = typing.MutableSet +Optional = typing.Optional +Pattern = typing.Pattern +Reversible = typing.Reversible +Sequence = typing.Sequence +Set = typing.Set +Sized = typing.Sized +TextIO = typing.TextIO +Tuple = typing.Tuple +Union = typing.Union +ValuesView = typing.ValuesView +cast = typing.cast +no_type_check = typing.no_type_check +no_type_check_decorator = typing.no_type_check_decorator diff --git a/script.module.typing_extensions/icon.png b/script.module.typing_extensions/resources/icon.png similarity index 100% rename from script.module.typing_extensions/icon.png rename to script.module.typing_extensions/resources/icon.png