diff --git a/pygbag/support/typing_extensions.py b/pygbag/support/typing_extensions.py new file mode 100644 index 0000000..c96bf90 --- /dev/null +++ b/pygbag/support/typing_extensions.py @@ -0,0 +1,2892 @@ +import abc +import collections +import collections.abc +import functools +import inspect +import operator +import sys +import types as _types +import typing +import warnings + +__all__ = [ + # Super-special typing primitives. + 'Any', + 'ClassVar', + 'Concatenate', + 'Final', + 'LiteralString', + 'ParamSpec', + 'ParamSpecArgs', + 'ParamSpecKwargs', + 'Self', + 'Type', + 'TypeVar', + 'TypeVarTuple', + 'Unpack', + + # ABCs (from collections.abc). + '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', + 'Doc', + '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', +] + +# 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. + + +class _Sentinel: + def __repr__(self): + return "" + + +_marker = _Sentinel() + + +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: + def _should_collect_from_parameters(t): + return isinstance(t, typing._GenericAlias) and not t._special + + +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.) +T = typing.TypeVar('T') # Any type. +KT = typing.TypeVar('KT') # Key type. +VT = typing.TypeVar('VT') # Value type. +T_co = typing.TypeVar('T_co', covariant=True) # Any type covariant containers. +T_contra = typing.TypeVar('T_contra', contravariant=True) # Ditto contravariant. + + +if sys.version_info >= (3, 11): + from typing import Any +else: + + class _AnyMeta(type): + def __instancecheck__(self, obj): + if self is Any: + raise TypeError("typing_extensions.Any cannot be used with isinstance()") + return super().__instancecheck__(obj) + + def __repr__(self): + 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) + + +ClassVar = typing.ClassVar + + +class _ExtensionsSpecialForm(typing._SpecialForm, _root=True): + def __repr__(self): + return 'typing_extensions.' + self._name + + +Final = 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 + cannot be subclassed. For example: + + class Base: + @final + def done(self) -> None: + ... + class Sub(Base): + def done(self) -> None: # Error reported by type checker + ... + @final + class Leaf: + ... + class Other(Leaf): # Error reported by type checker + ... + + 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 typing.TypeVar(name) + + +# 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 +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 _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): + if not isinstance(parameters, tuple): + parameters = (parameters,) + + 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: + + var: Literal[4] = 4 + + 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.""") + + +_overload_dummy = typing._overload_dummy + + +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 + + 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 clear_overloads(): + """Clear all overloads in the registry.""" + _overload_registry.clear() + + +# This is not a real generic class. Don't use outside annotations. +Type = typing.Type + +# Various ABCs mimicking those in collections.abc. +# A few are simply re-exported for completeness. +Awaitable = typing.Awaitable +Coroutine = typing.Coroutine +AsyncIterable = typing.AsyncIterable +AsyncIterator = typing.AsyncIterator +Deque = typing.Deque +ContextManager = typing.ContextManager +AsyncContextManager = typing.AsyncContextManager +DefaultDict = typing.DefaultDict +OrderedDict = typing.OrderedDict +Counter = typing.Counter +ChainMap = typing.ChainMap +AsyncGenerator = typing.AsyncGenerator +Text = typing.Text +TYPE_CHECKING = typing.TYPE_CHECKING + + +_PROTO_ALLOWLIST = { + 'collections.abc': [ + 'Callable', 'Awaitable', 'Iterable', 'Iterator', 'AsyncIterable', + 'Hashable', 'Sized', 'Container', 'Collection', 'Reversible', 'Buffer', + ], + 'contextlib': ['AbstractContextManager', 'AbstractAsyncContextManager'], + 'typing_extensions': ['Buffer'], +} + + +_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__", +} + +if sys.version_info >= (3, 9): + _EXCLUDED_ATTRS.add("__class_getitem__") + +if sys.version_info >= (3, 12): + _EXCLUDED_ATTRS.add("__type_params__") + +_EXCLUDED_ATTRS = frozenset(_EXCLUDED_ATTRS) + + +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 + + +def _caller(depth=2): + try: + return sys._getframe(depth).f_globals.get('__name__', '__main__') + except (AttributeError, ValueError): # For platforms without _getframe() + return None + + +# 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') + + # 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" + class _ProtocolMeta(type(typing.Protocol)): + # 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 __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") + + if abc.ABCMeta.__instancecheck__(cls, instance): + return True + + 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 + + return False + + def __eq__(cls, other): + # Hack so that typing.Generic.__class_getitem__ + # treats typing_extensions.Protocol + # as equivalent to typing.Protocol + if abc.ABCMeta.__eq__(cls, other) is True: + return True + return cls is Protocol and other is typing.Protocol + + # 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) + + @classmethod + def _proto_hook(cls, other): + if not cls.__dict__.get('_is_protocol', False): + return NotImplemented + + 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 + + # ...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 Protocol(typing.Generic, metaclass=_ProtocolMeta): + __doc__ = typing.Protocol.__doc__ + __slots__ = () + _is_protocol = True + _is_runtime_protocol = False + + def __init_subclass__(cls, *args, **kwargs): + super().__init_subclass__(*args, **kwargs) + + # 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__) + + # 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 + + +# The "runtime" alias exists for backwards compatibility. +runtime = runtime_checkable = typing.runtime_checkable + + +# Our version of runtime-checkable protocols is faster on Python 3.8-3.11 +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: + @runtime_checkable + class SupportsInt(Protocol): + """An ABC with one abstract method __int__.""" + __slots__ = () + + @abc.abstractmethod + def __int__(self) -> int: + pass + + @runtime_checkable + class SupportsFloat(Protocol): + """An ABC with one abstract method __float__.""" + __slots__ = () + + @abc.abstractmethod + def __float__(self) -> float: + pass + + @runtime_checkable + class SupportsComplex(Protocol): + """An ABC with one abstract method __complex__.""" + __slots__ = () + + @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 + + 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" + tp_dict = type.__new__(_TypedDictMeta, "Protocol", (*generic_base, dict), ns) + tp_dict.__name__ = name + if tp_dict.__qualname__ == "Protocol": + 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"): # 3.11+ + get_type_hints = typing.get_type_hints +else: # <=3.10 + # 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"): # 3.9+ + hint = typing.get_type_hints( + obj, globalns=globalns, localns=localns, include_extras=True + ) + else: # 3.8 + 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 +# 3.8 +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 +# 3.8-3.9 +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 + + 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") +# 3.8 +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: + if isinstance(type_param, ParamSpec) and default is ...: # ... not valid <3.11 + type_param.__default__ = default + else: + 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 (3.12+), 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 +# 3.8-3.9 +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") + +# 3.8-3.9 +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 + + +# 3.8-3.9 +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 + + # Flag in 3.8. + _special = False + + def __init__(self, origin, args): + super().__init__(args) + self.__origin__ = origin + self.__args__ = args + + def __repr__(self): + _type_repr = typing._type_repr + return (f'{_type_repr(self.__origin__)}' + f'[{", ".join(_type_repr(arg) for arg in self.__args__)}]') + + def __hash__(self): + return hash((self.__origin__, self.__args__)) + + # 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)) + ) + + +# 3.8-3.9 +@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. + + For example:: + + Callable[Concatenate[int, P], int] + + See PEP 612 for detailed information. + """ + return _concatenate_getitem(self, parameters) +# 3.8 +else: + class _ConcatenateForm(_ExtensionsSpecialForm, _root=True): + def __getitem__(self, parameters): + return _concatenate_getitem(self, parameters) + + 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. + + For example:: + + Callable[Concatenate[int, P], int] + + See PEP 612 for detailed information. + """) + +# 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. + + ``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. + + Using ``-> TypeGuard`` tells the static type checker that for a given + function: + + 1. The return value is a boolean. + 2. If the return value is ``True``, the type of its argument + is the type inside ``TypeGuard``. + + For example:: + + 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``. + ... + + 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. + + ``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,)) +# 3.8 +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. + + ``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. + + Using ``-> TypeGuard`` tells the static type checker that for a given + function: + + 1. The return value is a boolean. + 2. If the return value is ``True``, the type of its argument + is the type inside ``TypeGuard``. + + For example:: + + 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``. + ... + + 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. + + ``TypeGuard`` also works with type variables. For more information, see + PEP 647 (User-Defined Type Guards). + """) + + +# 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__ + + def __getattr__(self, item): + if item in {'__name__', '__qualname__'}: + return self._name + + raise AttributeError(item) + + def __mro_entries__(self, bases): + raise TypeError(f"Cannot subclass {self!r}") + + def __repr__(self): + return f'typing_extensions.{self._name}' + + def __reduce__(self): + return self._name + + def __call__(self, *args, **kwds): + raise TypeError(f"Cannot instantiate {self!r}") + + def __or__(self, other): + return typing.Union[self, other] + + def __ror__(self, other): + return typing.Union[other, self] + + 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()") + + @typing._tp_cache + def __getitem__(self, parameters): + return self._getitem(self, parameters) + + +if hasattr(typing, "LiteralString"): # 3.11+ + LiteralString = typing.LiteralString +else: + @_SpecialForm + def LiteralString(self, params): + """Represents an arbitrary literal string. + + Example:: + + 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. + + """ + raise TypeError(f"{self} is not subscriptable") + + +if hasattr(typing, "Self"): # 3.11+ + 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 + + """ + + raise TypeError(f"{self} is not subscriptable") + + +if hasattr(typing, "Never"): # 3.11+ + Never = typing.Never +else: + @_SpecialForm + def Never(self, params): + """The bottom type, a type that has no members. + + This can be used to define a function that should never be + called, or a function that never returns:: + + from typing_extensions import Never + + 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 + + """ + + raise TypeError(f"{self} is not subscriptable") + + +if hasattr(typing, 'Required'): # 3.11+ + Required = typing.Required + NotRequired = typing.NotRequired +elif sys.version_info[:2] >= (3, 9): # 3.9-3.10 + @_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, + ) + + 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,)) + + @_ExtensionsSpecialForm + def NotRequired(self, parameters): + """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, + ) + """ + item = typing._type_check(parameters, f'{self._name} accepts only a single type.') + return typing._GenericAlias(self, (item,)) + +else: # 3.8 + 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,)) + + Required = _RequiredForm( + 'Required', + doc="""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, + ) + + 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, + ) + """) + + +_UNPACK_DOC = """\ +Type unpack operator. + +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: + + # 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 + +From Python 3.11, this can also be done using the `*` operator: + + Foo[*tuple[int, str]] + class Bar(Generic[*Ts]): ... + +The operator can also be used along with a `TypedDict` to annotate +`**kwargs` in a function signature. For instance: + + 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]): ... + +Note that there is only some runtime checking of this operator. Not +everything the runtime allows may be accepted by static type checkers. + +For more information, see PEP 646 and PEP 692. +""" + + +if sys.version_info >= (3, 12): # PEP 692 changed the repr of Unpack[] + Unpack = typing.Unpack + + def _is_unpack(obj): + return get_origin(obj) is Unpack + +elif sys.version_info[:2] >= (3, 9): # 3.9+ + class _UnpackSpecialForm(_ExtensionsSpecialForm, _root=True): + def __init__(self, getitem): + super().__init__(getitem) + self.__doc__ = _UNPACK_DOC + + class _UnpackAlias(typing._GenericAlias, _root=True): + __class__ = typing.TypeVar + + @_UnpackSpecialForm + def Unpack(self, parameters): + item = typing._type_check(parameters, f'{self._name} accepts only a single type.') + return _UnpackAlias(self, (item,)) + + def _is_unpack(obj): + return isinstance(obj, _UnpackAlias) + +else: # 3.8 + 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,)) + + Unpack = _UnpackForm('Unpack', doc=_UNPACK_DOC) + + 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: # <=3.10 + class TypeVarTuple(_DefaultMixin): + """Type variable tuple. + + Usage:: + + Ts = TypeVarTuple('Ts') + + 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]``. + + Type variable tuples can be used in ``Generic`` declarations. + Consider the following example:: + + class Array(Generic[*Ts]): ... + + 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. + + 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]): + + 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] + + """ + + # Trick Generic __parameters__. + __class__ = typing.TypeVar + + def __iter__(self): + yield self.__unpacked__ + + def __init__(self, name, *, default=_marker): + self.__name__ = name + _DefaultMixin.__init__(self, default) + + # 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 object.__hash__(self) + + def __eq__(self, other): + return self is other + + def __reduce__(self): + return self.__name__ + + def __init_subclass__(self, *args, **kwds): + if '_root' not in kwds: + raise TypeError("Cannot subclass special typing classes") + + +if hasattr(typing, "reveal_type"): # 3.11+ + reveal_type = typing.reveal_type +else: # <=3.10 + def reveal_type(obj: T, /) -> T: + """Reveal the inferred type of a variable. + + When a static type checker encounters a call to ``reveal_type()``, + it will emit the inferred type of the argument:: + + x: int = 1 + reveal_type(x) + + Running a static type checker (e.g., ``mypy``) on this example + will produce output similar to 'Revealed type is "builtins.int"'. + + At runtime, the function prints the runtime type of the + argument and returns it unchanged. + + """ + print(f"Runtime type is {type(obj).__name__!r}", file=sys.stderr) + return obj + + +if hasattr(typing, "assert_never"): # 3.11+ + assert_never = typing.assert_never +else: # <=3.10 + def assert_never(arg: Never, /) -> Never: + """Assert to the type checker that a line of code is unreachable. + + Example:: + + 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. + + """ + raise AssertionError("Expected code to be unreachable") + + +if sys.version_info >= (3, 12): # 3.12+ + # dataclass_transform exists in 3.11 but lacks the frozen_default parameter + dataclass_transform = typing.dataclass_transform +else: # <=3.11 + 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 + + @create_model + class CustomerModel: + id: int + name: str + + # Used on a base class + @dataclass_transform() + class ModelBase: ... + + class CustomerModel(ModelBase): + id: int + name: str + + # Used on a metaclass + @dataclass_transform() + class ModelMeta(type): ... + + 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. + + """ + 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 + + +if hasattr(typing, "override"): # 3.12+ + override = typing.override +else: # <=3.11 + _F = typing.TypeVar("_F", bound=typing.Callable[..., typing.Any]) + + def override(arg: _F, /) -> _F: + """Indicate that a method is intended to override a method in a base class. + + Usage: + + class Base: + def method(self) -> None: ... + pass + + class Child(Base): + @override + def method(self) -> None: + super().method() + + 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. + + There is no runtime checking of these properties. The decorator + sets the ``__override__`` attribute to ``True`` on the decorated object + to allow runtime introspection. + + See PEP 698 for details. + + """ + 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 + + +if hasattr(typing, "deprecated"): + deprecated = typing.deprecated +else: + _T = typing.TypeVar("_T") + + 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. + + Usage: + + @deprecated("Use B instead") + class A: + pass + + @deprecated("Use g instead") + def f(): + pass + + @overload + @deprecated("int support is deprecated") + def g(x: int) -> int: ... + @overload + def g(x: str) -> int: ... + + When this decorator is applied to an object, the type checker + will generate a diagnostic on usage of the deprecated object. + + 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. + + 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()``. + + See PEP 702 for details. + + """ + 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 3.13. +# 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. + + Usage:: + + class Employee(NamedTuple): + name: str + id: int + + This is equivalent to:: + + 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 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 + + +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. + + """ + + # As a courtesy, register the most common stdlib buffer classes. + Buffer.register(memoryview) + Buffer.register(bytearray) + Buffer.register(bytes) + + +# 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__`. + + Examples:: + + 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.__dict__.get("__orig_bases__", cls.__bases__) + except AttributeError: + raise TypeError( + f'Expected an instance of type, not {type(cls).__name__!r}' + ) from None + + +# 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 + """ + + 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 f'{self.__module__}.{self.__qualname__}' + + def __reduce__(self): + return self.__qualname__ + + if sys.version_info >= (3, 10): + # PEP 604 methods + # It doesn't make sense to have these methods on Python <3.10 + + def __or__(self, other): + return typing.Union[self, other] + + def __ror__(self, other): + return typing.Union[other, self] + + +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 TypeAliasType: + """Create named, parameterized type aliases. + + This provides a backport of the new `type` statement in Python 3.12: + + 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)'). + + """ + + 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 + + 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) -> str: + return self.__name__ + + 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 __reduce__(self): + return self.__name__ + + def __init_subclass__(cls, *args, **kwargs): + raise TypeError( + "type 'typing_extensions.TypeAliasType' is not an acceptable base type" + ) + + # The presence of this method convinces typing._type_check + # that TypeAliasTypes are types. + def __call__(self): + raise TypeError("Type alias is not callable") + + 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] + + def __ror__(self, left): + if not _is_unionable(left): + return NotImplemented + return typing.Union[left, self] + + +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 + """ + return ( + isinstance(tp, type) + and getattr(tp, '_is_protocol', False) + and tp is not Protocol + and tp is not typing.Protocol + ) + + 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)) + + +if hasattr(typing, "Doc"): + Doc = typing.Doc +else: + class Doc: + """Define the documentation of a type annotation using ``Annotated``, to be + used in class attributes, function and method parameters, return values, + and variables. + + The value should be a positional-only string literal to allow static tools + like editors and documentation generators to use it. + + This complements docstrings. + + The string value passed is available in the attribute ``documentation``. + + Example:: + + >>> from typing_extensions import Annotated, Doc + >>> def hi(to: Annotated[str, Doc("Who to say hi to")]) -> None: ... + """ + def __init__(self, documentation: str, /) -> None: + self.documentation = documentation + + def __repr__(self) -> str: + return f"Doc({self.documentation!r})" + + def __hash__(self) -> int: + return hash(self.documentation) + + def __eq__(self, other: object) -> bool: + if not isinstance(other, Doc): + return NotImplemented + return self.documentation == other.documentation + + +# 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