| import abc |
| import collections |
| import contextlib |
| import sys |
| 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 |
| |
| |
| # Please keep __all__ alphabetized within each category. |
| __all__ = [ |
| # Super-special typing primitives. |
| 'ClassVar', |
| 'Final', |
| 'Type', |
| |
| # 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', |
| |
| # Concrete collection types. |
| 'ContextManager', |
| 'Counter', |
| 'Deque', |
| 'DefaultDict', |
| 'TypedDict', |
| |
| # One-off things. |
| 'final', |
| 'IntVar', |
| 'Literal', |
| 'NewType', |
| 'overload', |
| 'Text', |
| 'TYPE_CHECKING', |
| ] |
| |
| # 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']) |
| |
| |
| # 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') |
| |
| 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().") |
| |
| def __subclasscheck__(self, cls): |
| raise TypeError("NoReturn cannot be used with issubclass().") |
| |
| NoReturn = _NoReturn(_root=True) |
| 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().") |
| |
| 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__ = () |
| |
| |
| # 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. |
| 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) |
| 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 |
| |
| 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) |
| |
| 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. |
| |
| 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(). |
| """ |
| |
| __type__ = None |
| |
| # On older versions of typing there is an internal class named "Final". |
| 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 |
| |
| def __getitem__(self, parameters): |
| item = typing._type_check(parameters, |
| '{} accepts only single type'.format(self._name)) |
| return _GenericAlias(self, (item,)) |
| |
| Final = _FinalForm('Final', |
| doc="""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.""") |
| 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'): |
| final = typing.final |
| else: |
| 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. |
| """ |
| return f |
| |
| |
| def IntVar(name): |
| return TypeVar(name) |
| |
| |
| if hasattr(typing, 'Literal'): |
| Literal = typing.Literal |
| elif sys.version_info[:2] >= (3, 7): |
| class _LiteralForm(typing._SpecialForm, _root=True): |
| |
| def __repr__(self): |
| return 'typing_extensions.' + self._name |
| |
| def __getitem__(self, parameters): |
| return _GenericAlias(self, parameters) |
| |
| Literal = _LiteralForm('Literal', |
| 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.""") |
| 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. |
| |
| Literal[...] cannot be subclassed. There is no runtime checking |
| verifying that the parameter is actually a value instead of a type. |
| """ |
| |
| __slots__ = ('__values__',) |
| |
| def __init__(self, values=None, **kwds): |
| self.__values__ = values |
| |
| 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 |
| |
| def __repr__(self): |
| r = super().__repr__() |
| if self.__values__ is not None: |
| r += '[{}]'.format(', '.join(map(typing._type_repr, self.__values__))) |
| return r |
| |
| 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 |
| |
| Literal = _Literal(_root=True) |
| else: |
| class _LiteralMeta(typing.TypingMeta): |
| """Metaclass for Literal""" |
| |
| 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 |
| |
| def __instancecheck__(self, obj): |
| raise TypeError("Literal cannot be used with isinstance().") |
| |
| def __subclasscheck__(self, cls): |
| raise TypeError("Literal cannot be used with issubclass().") |
| |
| 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) |
| |
| def _eval_type(self, globalns, localns): |
| return self |
| |
| def __repr__(self): |
| r = super().__repr__() |
| if self.__values__ is not None: |
| r += '[{}]'.format(', '.join(map(typing._type_repr, self.__values__))) |
| return r |
| |
| 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 |
| |
| 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 |
| |
| 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. |
| """ |
| |
| __values__ = 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.") |
| |
| |
| 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 |
| """ |
| return _overload_dummy |
| |
| |
| # 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) |
| |
| class Type(typing.Generic[CT_co], extra=type): |
| """A special construct usable to annotate class objects. |
| |
| For example, suppose we have the following classes:: |
| |
| class User: ... # Abstract base for User classes |
| class BasicUser(User): ... |
| class ProUser(User): ... |
| class TeamUser(User): ... |
| |
| And a function that takes a class argument that's a subclass of |
| User and returns an instance of the corresponding class:: |
| |
| 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) |
| |
| At this point the type checker knows that joe has type BasicUser. |
| """ |
| |
| __slots__ = () |
| |
| |
| # Various ABCs mimicking those in collections.abc. |
| # A few are simply re-exported for completeness. |
| |
| def _define_guard(type_name): |
| """ |
| Returns True if the given type isn't defined in typing but |
| is defined in collections_abc. |
| |
| 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 _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 |
| |
| |
| if _define_guard('Awaitable'): |
| class Awaitable(typing.Generic[T_co], metaclass=_ExtensionsGenericMeta, |
| extra=collections_abc.Awaitable): |
| __slots__ = () |
| |
| |
| if _define_guard('Coroutine'): |
| class Coroutine(Awaitable[V_co], typing.Generic[T_co, T_contra, V_co], |
| metaclass=_ExtensionsGenericMeta, |
| extra=collections_abc.Coroutine): |
| __slots__ = () |
| |
| |
| if _define_guard('AsyncIterable'): |
| class AsyncIterable(typing.Generic[T_co], |
| metaclass=_ExtensionsGenericMeta, |
| extra=collections_abc.AsyncIterable): |
| __slots__ = () |
| |
| |
| if _define_guard('AsyncIterator'): |
| class AsyncIterator(AsyncIterable[T_co], |
| metaclass=_ExtensionsGenericMeta, |
| extra=collections_abc.AsyncIterator): |
| __slots__ = () |
| |
| |
| 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) |
| else: |
| class Deque(collections.deque, typing.MutableSequence[T], |
| metaclass=_ExtensionsGenericMeta, |
| extra=collections.deque): |
| __slots__ = () |
| |
| def __new__(cls, *args, **kwds): |
| if cls._gorg is Deque: |
| return collections.deque(*args, **kwds) |
| return _generic_new(collections.deque, cls, *args, **kwds) |
| |
| |
| if hasattr(typing, 'ContextManager'): |
| ContextManager = typing.ContextManager |
| elif hasattr(contextlib, 'AbstractContextManager'): |
| class ContextManager(typing.Generic[T_co], |
| metaclass=_ExtensionsGenericMeta, |
| extra=contextlib.AbstractContextManager): |
| __slots__ = () |
| else: |
| class ContextManager(typing.Generic[T_co]): |
| __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 |
| |
| |
| 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): |
| __slots__ = () |
| |
| __all__.append('AsyncContextManager') |
| elif sys.version_info[:2] >= (3, 5): |
| exec(""" |
| class AsyncContextManager(typing.Generic[T_co]): |
| __slots__ = () |
| |
| async def __aenter__(self): |
| return self |
| |
| @abc.abstractmethod |
| async def __aexit__(self, exc_type, exc_value, traceback): |
| return None |
| |
| @classmethod |
| def __subclasshook__(cls, C): |
| if cls is AsyncContextManager: |
| return _check_methods_in_mro(C, "__aenter__", "__aexit__") |
| return NotImplemented |
| |
| __all__.append('AsyncContextManager') |
| """) |
| |
| |
| if hasattr(typing, 'DefaultDict'): |
| DefaultDict = typing.DefaultDict |
| elif _geqv_defined: |
| class DefaultDict(collections.defaultdict, typing.MutableMapping[KT, VT], |
| metaclass=_ExtensionsGenericMeta, |
| extra=collections.defaultdict): |
| |
| __slots__ = () |
| |
| 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): |
| |
| __slots__ = () |
| |
| def __new__(cls, *args, **kwds): |
| if cls._gorg is DefaultDict: |
| return collections.defaultdict(*args, **kwds) |
| return _generic_new(collections.defaultdict, cls, *args, **kwds) |
| |
| |
| 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)) |
| |
| class Counter(collections.Counter, |
| typing.Dict[T, int], |
| metaclass=_CounterMeta, |
| extra=collections.Counter): |
| |
| __slots__ = () |
| |
| def __new__(cls, *args, **kwds): |
| if _geqv(cls, Counter): |
| return collections.Counter(*args, **kwds) |
| return _generic_new(collections.Counter, cls, *args, **kwds) |
| |
| elif _geqv_defined: |
| class Counter(collections.Counter, |
| typing.Dict[T, int], |
| metaclass=_ExtensionsGenericMeta, extra=collections.Counter): |
| |
| __slots__ = () |
| |
| def __new__(cls, *args, **kwds): |
| if _geqv(cls, Counter): |
| return collections.Counter(*args, **kwds) |
| return _generic_new(collections.Counter, cls, *args, **kwds) |
| |
| else: |
| class Counter(collections.Counter, |
| typing.Dict[T, int], |
| metaclass=_ExtensionsGenericMeta, extra=collections.Counter): |
| |
| __slots__ = () |
| |
| def __new__(cls, *args, **kwds): |
| if cls._gorg is Counter: |
| return collections.Counter(*args, **kwds) |
| return _generic_new(collections.Counter, cls, *args, **kwds) |
| |
| |
| 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): |
| |
| __slots__ = () |
| |
| 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): |
| |
| __slots__ = () |
| |
| def __new__(cls, *args, **kwds): |
| if cls._gorg is ChainMap: |
| return collections.ChainMap(*args, **kwds) |
| return _generic_new(collections.ChainMap, cls, *args, **kwds) |
| |
| __all__.append('ChainMap') |
| |
| |
| if _define_guard('AsyncGenerator'): |
| class AsyncGenerator(AsyncIterator[T_co], typing.Generic[T_co, T_contra], |
| metaclass=_ExtensionsGenericMeta, |
| extra=collections_abc.AsyncGenerator): |
| __slots__ = () |
| |
| |
| 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:: |
| |
| 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 new_type(x): |
| return x |
| |
| new_type.__name__ = name |
| new_type.__supertype__ = tp |
| return new_type |
| |
| |
| if hasattr(typing, 'Text'): |
| Text = typing.Text |
| else: |
| Text = str |
| |
| |
| 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 _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 |
| |
| |
| 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 |
| |
| |
| _PROTO_WHITELIST = ['Callable', 'Awaitable', |
| 'Iterable', 'Iterator', 'AsyncIterable', 'AsyncIterator', |
| 'Hashable', 'Sized', 'Container', 'Collection', 'Reversible', |
| 'ContextManager', 'AsyncContextManager'] |
| |
| |
| 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 |
| |
| |
| def _is_callable_members_only(cls): |
| return all(callable(getattr(cls, attr, None)) for attr in _get_protocol_attrs(cls)) |
| |
| |
| if hasattr(typing, 'Protocol'): |
| Protocol = typing.Protocol |
| elif HAVE_PROTOCOLS and not PEP_560: |
| class _ProtocolMeta(GenericMeta): |
| """Internal metaclass for Protocol. |
| |
| 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 |
| |
| 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: |
| ... |
| |
| Such classes are primarily used with static type checkers that recognize |
| structural subtyping (static duck-typing), for example:: |
| |
| class C: |
| def meth(self) -> int: |
| return 0 |
| |
| def func(x: Proto) -> int: |
| return x.meth() |
| |
| func(C()) # Passes static type check |
| |
| 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. |
| |
| Protocol classes can be generic, they are defined as:: |
| |
| 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:: |
| |
| class C: |
| def meth(self) -> int: |
| return 0 |
| |
| def func(x: Proto) -> int: |
| return x.meth() |
| |
| func(C()) # Passes static type check |
| |
| 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. |
| |
| Protocol classes can be generic, they are defined as:: |
| |
| class GenProto(Protocol[T]): |
| def meth(self) -> T: |
| ... |
| """ |
| __slots__ = () |
| _is_protocol = True |
| |
| 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) |
| |
| @_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) |
| |
| 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 |
| |
| # We have nothing more to do for non-protocols. |
| if not cls._is_protocol: |
| return |
| |
| # 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) |
| |
| def _no_init(self, *args, **kwargs): |
| if type(self)._is_protocol: |
| raise TypeError('Protocols cannot be instantiated') |
| cls.__init__ = _no_init |
| |
| |
| 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. |
| |
| 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 |
| |
| |
| if HAVE_PROTOCOLS: |
| # Exists for backwards compatibility. |
| runtime = runtime_checkable |
| |
| |
| 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__ = '($cls, _typename, _fields=None, /, **kwargs)' |
| |
| def _typeddict_new(*args, total=True, **kwargs): |
| if not args: |
| raise TypeError('TypedDict.__new__(): not enough arguments') |
| _, args = args[0], args[1:] # allow the "cls" keyword be passed |
| if args: |
| typename, args = args[0], args[1:] # allow the "_typename" keyword be passed |
| elif '_typename' in kwargs: |
| typename = kwargs.pop('_typename') |
| import warnings |
| warnings.warn("Passing '_typename' as keyword argument is deprecated", |
| DeprecationWarning, stacklevel=2) |
| else: |
| raise TypeError("TypedDict.__new__() missing 1 required positional " |
| "argument: '_typename'") |
| if args: |
| try: |
| fields, = args # allow the "_fields" keyword be passed |
| except ValueError: |
| raise TypeError('TypedDict.__new__() takes from 2 to 3 ' |
| 'positional arguments but {} ' |
| 'were given'.format(len(args) + 2)) |
| elif '_fields' in kwargs and len(kwargs) == 1: |
| fields = kwargs.pop('_fields') |
| import warnings |
| warnings.warn("Passing '_fields' as keyword argument is deprecated", |
| DeprecationWarning, stacklevel=2) |
| else: |
| fields = None |
| |
| if fields is None: |
| fields = kwargs |
| elif kwargs: |
| raise TypeError("TypedDict takes either a dict or keyword arguments," |
| " but not both") |
| |
| ns = {'__annotations__': dict(fields), '__total__': total} |
| try: |
| # Setting correct module is necessary to make typed dict classes pickleable. |
| ns['__module__'] = sys._getframe(1).f_globals.get('__name__', '__main__') |
| except (AttributeError, ValueError): |
| pass |
| |
| return _TypedDictMeta(typename, (), ns) |
| |
| _typeddict_new.__text_signature__ = ('($cls, _typename, _fields=None,' |
| ' /, *, total=True, **kwargs)') |
| |
| 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) |
| |
| 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() |
| |
| 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) |
| if total: |
| required_keys.update(own_annotation_keys) |
| else: |
| optional_keys.update(own_annotation_keys) |
| |
| 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 |
| |
| __instancecheck__ = __subclasscheck__ = _check_fails |
| |
| TypedDict = _TypedDictMeta('TypedDict', (dict,), {}) |
| TypedDict.__module__ = __name__ |
| TypedDict.__doc__ = \ |
| """A simple typed name space. At runtime it is equivalent to a plain dict. |
| |
| 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 |
| |
| 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 two additional equivalent forms:: |
| |
| Point2D = TypedDict('Point2D', x=int, y=int, label=str) |
| Point2D = TypedDict('Point2D', {'x': int, 'y': int, 'label': str}) |
| |
| The class syntax is only supported in Python 3.6+, while two other |
| syntax forms work for Python 2.7 and 3.2+ |
| """ |
| |
| |
| # 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. |
| |
| 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 "typing_extensions.Annotated[{}, {}]".format( |
| typing._type_repr(self.__origin__), |
| ", ".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.") |
| |
| @_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) |
| |
| def __init_subclass__(cls, *args, **kwargs): |
| raise TypeError( |
| "Cannot subclass {}.Annotated".format(cls.__module__) |
| ) |
| |
| 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 |
| |
| 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'). |
| |
| 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. |
| """ |
| 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()} |
| |
| 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('__') |
| |
| # 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. |
| |
| class AnnotatedMeta(typing.GenericMeta): |
| """Metaclass for Annotated""" |
| |
| 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) |
| |
| @property |
| def __metadata__(self): |
| return self._subs_tree()[2] |
| |
| 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 |
| |
| 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, |
| ) |
| |
| 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) |
| |
| def __instancecheck__(self, obj): |
| raise TypeError("Annotated cannot be used with isinstance().") |
| |
| def __subclasscheck__(self, cls): |
| raise TypeError("Annotated cannot be used with issubclass().") |
| |
| class Annotated(metaclass=AnnotatedMeta): |
| """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, the remaining |
| arguments are kept as a tuple in the __metadata__ 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()] |
| """ |
| |
| # 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 |
| |
| 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 |
| """ |
| if isinstance(tp, _AnnotatedAlias): |
| return Annotated |
| if isinstance(tp, _GenericAlias): |
| return tp.__origin__ |
| if tp is Generic: |
| return 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, _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 () |