| """ |
| The typing module: Support for gradual typing as defined by PEP 484. |
| |
| At large scale, the structure of the module is following: |
| * Imports and exports, all public names should be explicitly added to __all__. |
| * Internal helper functions: these should never be used in code outside this module. |
| * _SpecialForm and its instances (special forms): |
| Any, NoReturn, ClassVar, Union, Optional, Concatenate |
| * Classes whose instances can be type arguments in addition to types: |
| ForwardRef, TypeVar and ParamSpec |
| * The core of internal generics API: _GenericAlias and _VariadicGenericAlias, the latter is |
| currently only used by Tuple and Callable. All subscripted types like X[int], Union[int, str], |
| etc., are instances of either of these classes. |
| * The public counterpart of the generics API consists of two classes: Generic and Protocol. |
| * Public helper functions: get_type_hints, overload, cast, no_type_check, |
| no_type_check_decorator. |
| * Generic aliases for collections.abc ABCs and few additional protocols. |
| * Special types: NewType, NamedTuple, TypedDict. |
| * Wrapper submodules for re and io related types. |
| """ |
| |
| from abc import abstractmethod, ABCMeta |
| import ast |
| import collections |
| import collections.abc |
| import contextlib |
| import functools |
| import operator |
| import re as stdlib_re # Avoid confusion with the re we export. |
| import sys |
| import types |
| from types import WrapperDescriptorType, MethodWrapperType, MethodDescriptorType, GenericAlias |
| |
| # Please keep __all__ alphabetized within each category. |
| __all__ = [ |
| # Super-special typing primitives. |
| 'Annotated', |
| 'Any', |
| 'Callable', |
| 'ClassVar', |
| 'Concatenate', |
| 'Final', |
| 'ForwardRef', |
| 'Generic', |
| 'Literal', |
| 'Optional', |
| 'ParamSpec', |
| 'Protocol', |
| 'Tuple', |
| 'Type', |
| 'TypeVar', |
| 'Union', |
| |
| # ABCs (from collections.abc). |
| 'AbstractSet', # collections.abc.Set. |
| 'ByteString', |
| 'Container', |
| 'ContextManager', |
| 'Hashable', |
| 'ItemsView', |
| 'Iterable', |
| 'Iterator', |
| 'KeysView', |
| 'Mapping', |
| 'MappingView', |
| 'MutableMapping', |
| 'MutableSequence', |
| 'MutableSet', |
| 'Sequence', |
| 'Sized', |
| 'ValuesView', |
| 'Awaitable', |
| 'AsyncIterator', |
| 'AsyncIterable', |
| 'Coroutine', |
| 'Collection', |
| 'AsyncGenerator', |
| 'AsyncContextManager', |
| |
| # Structural checks, a.k.a. protocols. |
| 'Reversible', |
| 'SupportsAbs', |
| 'SupportsBytes', |
| 'SupportsComplex', |
| 'SupportsFloat', |
| 'SupportsIndex', |
| 'SupportsInt', |
| 'SupportsRound', |
| |
| # Concrete collection types. |
| 'ChainMap', |
| 'Counter', |
| 'Deque', |
| 'Dict', |
| 'DefaultDict', |
| 'List', |
| 'OrderedDict', |
| 'Set', |
| 'FrozenSet', |
| 'NamedTuple', # Not really a type. |
| 'TypedDict', # Not really a type. |
| 'Generator', |
| |
| # One-off things. |
| 'AnyStr', |
| 'cast', |
| 'final', |
| 'get_args', |
| 'get_origin', |
| 'get_type_hints', |
| 'is_typeddict', |
| 'NewType', |
| 'no_type_check', |
| 'no_type_check_decorator', |
| 'NoReturn', |
| 'overload', |
| 'runtime_checkable', |
| 'Text', |
| 'TYPE_CHECKING', |
| 'TypeAlias', |
| ] |
| |
| # The pseudo-submodules 're' and 'io' are part of the public |
| # namespace, but excluded from __all__ because they might stomp on |
| # legitimate imports of those modules. |
| |
| |
| def _type_convert(arg): |
| """For converting None to type(None), and strings to ForwardRef.""" |
| if arg is None: |
| return type(None) |
| if isinstance(arg, str): |
| return ForwardRef(arg) |
| return arg |
| |
| |
| def _type_check(arg, msg, is_argument=True): |
| """Check that the argument is a type, and return it (internal helper). |
| |
| As a special case, accept None and return type(None) instead. Also wrap strings |
| into ForwardRef instances. Consider several corner cases, for example plain |
| special forms like Union are not valid, while Union[int, str] is OK, etc. |
| The msg argument is a human-readable error message, e.g:: |
| |
| "Union[arg, ...]: arg should be a type." |
| |
| We append the repr() of the actual value (truncated to 100 chars). |
| """ |
| invalid_generic_forms = (Generic, Protocol) |
| if is_argument: |
| invalid_generic_forms = invalid_generic_forms + (ClassVar, Final) |
| |
| arg = _type_convert(arg) |
| if (isinstance(arg, _GenericAlias) and |
| arg.__origin__ in invalid_generic_forms): |
| raise TypeError(f"{arg} is not valid as type argument") |
| if arg in (Any, NoReturn): |
| return arg |
| if isinstance(arg, _SpecialForm) or arg in (Generic, Protocol): |
| raise TypeError(f"Plain {arg} is not valid as type argument") |
| if isinstance(arg, (type, TypeVar, ForwardRef, types.Union, ParamSpec)): |
| return arg |
| if not callable(arg): |
| raise TypeError(f"{msg} Got {arg!r:.100}.") |
| return arg |
| |
| |
| def _type_repr(obj): |
| """Return the repr() of an object, special-casing types (internal helper). |
| |
| If obj is a type, we return a shorter version than the default |
| type.__repr__, based on the module and qualified name, which is |
| typically enough to uniquely identify a type. For everything |
| else, we fall back on repr(obj). |
| """ |
| if isinstance(obj, types.GenericAlias): |
| return repr(obj) |
| if isinstance(obj, type): |
| if obj.__module__ == 'builtins': |
| return obj.__qualname__ |
| return f'{obj.__module__}.{obj.__qualname__}' |
| if obj is ...: |
| return('...') |
| if isinstance(obj, types.FunctionType): |
| return obj.__name__ |
| return repr(obj) |
| |
| |
| def _collect_type_vars(types): |
| """Collect all type variable-like variables contained |
| in types in order of first appearance (lexicographic order). For example:: |
| |
| _collect_type_vars((T, List[S, T])) == (T, S) |
| """ |
| tvars = [] |
| for t in types: |
| if isinstance(t, _TypeVarLike) and t not in tvars: |
| tvars.append(t) |
| if isinstance(t, (_GenericAlias, GenericAlias)): |
| tvars.extend([t for t in t.__parameters__ if t not in tvars]) |
| return tuple(tvars) |
| |
| |
| def _check_generic(cls, parameters, elen): |
| """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") |
| alen = len(parameters) |
| if alen != elen: |
| raise TypeError(f"Too {'many' if alen > elen else 'few'} parameters for {cls};" |
| f" actual {alen}, expected {elen}") |
| |
| def _prepare_paramspec_params(cls, params): |
| """Prepares the parameters for a Generic containing ParamSpec |
| variables (internal helper). |
| """ |
| # Special case where Z[[int, str, bool]] == Z[int, str, bool] in PEP 612. |
| if len(cls.__parameters__) == 1 and len(params) > 1: |
| return (params,) |
| else: |
| _params = [] |
| # Convert lists to tuples to help other libraries cache the results. |
| for p, tvar in zip(params, cls.__parameters__): |
| if isinstance(tvar, ParamSpec) and isinstance(p, list): |
| p = tuple(p) |
| _params.append(p) |
| return tuple(_params) |
| |
| def _deduplicate(params): |
| # Weed out strict duplicates, preserving the first of each occurrence. |
| all_params = set(params) |
| if len(all_params) < len(params): |
| new_params = [] |
| for t in params: |
| if t in all_params: |
| new_params.append(t) |
| all_params.remove(t) |
| params = new_params |
| assert not all_params, all_params |
| return params |
| |
| |
| def _remove_dups_flatten(parameters): |
| """An internal helper for Union creation and substitution: flatten Unions |
| among parameters, then remove duplicates. |
| """ |
| # Flatten out Union[Union[...], ...]. |
| params = [] |
| for p in parameters: |
| if isinstance(p, (_UnionGenericAlias, types.Union)): |
| params.extend(p.__args__) |
| elif isinstance(p, tuple) and len(p) > 0 and p[0] is Union: |
| params.extend(p[1:]) |
| else: |
| params.append(p) |
| |
| return tuple(_deduplicate(params)) |
| |
| |
| 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) |
| |
| |
| _cleanups = [] |
| |
| |
| def _tp_cache(func=None, /, *, typed=False): |
| """Internal wrapper caching __getitem__ of generic types with a fallback to |
| original function for non-hashable arguments. |
| """ |
| def decorator(func): |
| cached = functools.lru_cache(typed=typed)(func) |
| _cleanups.append(cached.cache_clear) |
| |
| @functools.wraps(func) |
| def inner(*args, **kwds): |
| try: |
| return cached(*args, **kwds) |
| except TypeError: |
| pass # All real errors (not unhashable args) are raised below. |
| return func(*args, **kwds) |
| return inner |
| |
| if func is not None: |
| return decorator(func) |
| |
| return decorator |
| |
| def _eval_type(t, globalns, localns, recursive_guard=frozenset()): |
| """Evaluate all forward references in the given type t. |
| For use of globalns and localns see the docstring for get_type_hints(). |
| recursive_guard is used to prevent prevent infinite recursion |
| with recursive ForwardRef. |
| """ |
| if isinstance(t, ForwardRef): |
| return t._evaluate(globalns, localns, recursive_guard) |
| if isinstance(t, (_GenericAlias, GenericAlias)): |
| ev_args = tuple(_eval_type(a, globalns, localns, recursive_guard) for a in t.__args__) |
| if ev_args == t.__args__: |
| return t |
| if isinstance(t, GenericAlias): |
| return GenericAlias(t.__origin__, ev_args) |
| else: |
| return t.copy_with(ev_args) |
| return t |
| |
| |
| class _Final: |
| """Mixin to prohibit subclassing""" |
| |
| __slots__ = ('__weakref__',) |
| |
| def __init_subclass__(self, /, *args, **kwds): |
| if '_root' not in kwds: |
| raise TypeError("Cannot subclass special typing classes") |
| |
| class _Immutable: |
| """Mixin to indicate that object should not be copied.""" |
| __slots__ = () |
| |
| def __copy__(self): |
| return self |
| |
| def __deepcopy__(self, memo): |
| return self |
| |
| |
| # Internal indicator of special typing constructs. |
| # See __doc__ instance attribute for specific docs. |
| class _SpecialForm(_Final, _root=True): |
| __slots__ = ('_name', '__doc__', '_getitem') |
| |
| def __init__(self, getitem): |
| self._getitem = getitem |
| self._name = getitem.__name__ |
| self.__doc__ = getitem.__doc__ |
| |
| def __mro_entries__(self, bases): |
| raise TypeError(f"Cannot subclass {self!r}") |
| |
| def __repr__(self): |
| return 'typing.' + self._name |
| |
| def __reduce__(self): |
| return self._name |
| |
| def __call__(self, *args, **kwds): |
| raise TypeError(f"Cannot instantiate {self!r}") |
| |
| 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()") |
| |
| @_tp_cache |
| def __getitem__(self, parameters): |
| return self._getitem(self, parameters) |
| |
| |
| class _LiteralSpecialForm(_SpecialForm, _root=True): |
| @_tp_cache(typed=True) |
| def __getitem__(self, parameters): |
| return self._getitem(self, parameters) |
| |
| |
| @_SpecialForm |
| def Any(self, parameters): |
| """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 |
| or class checks. |
| """ |
| raise TypeError(f"{self} is not subscriptable") |
| |
| @_SpecialForm |
| def NoReturn(self, parameters): |
| """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. |
| """ |
| raise TypeError(f"{self} is not subscriptable") |
| |
| @_SpecialForm |
| def ClassVar(self, parameters): |
| """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(). |
| """ |
| item = _type_check(parameters, f'{self} accepts only single type.') |
| return _GenericAlias(self, (item,)) |
| |
| @_SpecialForm |
| def Final(self, parameters): |
| """Special typing construct to indicate final names to type checkers. |
| |
| A final 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. |
| """ |
| item = _type_check(parameters, f'{self} accepts only single type.') |
| return _GenericAlias(self, (item,)) |
| |
| @_SpecialForm |
| def Union(self, parameters): |
| """Union type; Union[X, Y] means either X or Y. |
| |
| To define a union, use e.g. Union[int, str]. Details: |
| - The arguments must be types and there must be at least one. |
| - None as an argument is a special case and is replaced by |
| type(None). |
| - Unions of unions are flattened, e.g.:: |
| |
| Union[Union[int, str], float] == Union[int, str, float] |
| |
| - Unions of a single argument vanish, e.g.:: |
| |
| Union[int] == int # The constructor actually returns int |
| |
| - Redundant arguments are skipped, e.g.:: |
| |
| Union[int, str, int] == Union[int, str] |
| |
| - When comparing unions, the argument order is ignored, e.g.:: |
| |
| Union[int, str] == Union[str, int] |
| |
| - You cannot subclass or instantiate a union. |
| - You can use Optional[X] as a shorthand for Union[X, None]. |
| """ |
| if parameters == (): |
| raise TypeError("Cannot take a Union of no types.") |
| if not isinstance(parameters, tuple): |
| parameters = (parameters,) |
| msg = "Union[arg, ...]: each arg must be a type." |
| parameters = tuple(_type_check(p, msg) for p in parameters) |
| parameters = _remove_dups_flatten(parameters) |
| if len(parameters) == 1: |
| return parameters[0] |
| return _UnionGenericAlias(self, parameters) |
| |
| @_SpecialForm |
| def Optional(self, parameters): |
| """Optional type. |
| |
| Optional[X] is equivalent to Union[X, None]. |
| """ |
| arg = _type_check(parameters, f"{self} requires a single type.") |
| return Union[arg, type(None)] |
| |
| @_LiteralSpecialForm |
| def Literal(self, parameters): |
| """Special typing form to define literal types (a.k.a. value types). |
| |
| This form can be used to indicate to type checkers that the corresponding |
| variable or function parameter has a value equivalent to the provided |
| literal (or one of several literals): |
| |
| def validate_simple(data: Any) -> Literal[True]: # always returns True |
| ... |
| |
| MODE = Literal['r', 'rb', 'w', 'wb'] |
| def open_helper(file: str, mode: MODE) -> str: |
| ... |
| |
| open_helper('/some/path', 'r') # Passes type check |
| open_helper('/other/path', 'typo') # Error in type checker |
| |
| Literal[...] cannot be subclassed. At runtime, an arbitrary value |
| is allowed as type argument to Literal[...], but type checkers may |
| impose restrictions. |
| """ |
| # There is no '_type_check' call because arguments to Literal[...] are |
| # values, not types. |
| if not isinstance(parameters, tuple): |
| parameters = (parameters,) |
| |
| parameters = _flatten_literal_params(parameters) |
| |
| try: |
| parameters = tuple(p for p, _ in _deduplicate(list(_value_and_type_iter(parameters)))) |
| except TypeError: # unhashable parameters |
| pass |
| |
| return _LiteralGenericAlias(self, parameters) |
| |
| |
| @_SpecialForm |
| 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") |
| |
| |
| @_SpecialForm |
| 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. |
| """ |
| 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(_type_check(p, msg) for p in parameters) |
| return _ConcatenateGenericAlias(self, parameters) |
| |
| |
| class ForwardRef(_Final, _root=True): |
| """Internal wrapper to hold a forward reference.""" |
| |
| __slots__ = ('__forward_arg__', '__forward_code__', |
| '__forward_evaluated__', '__forward_value__', |
| '__forward_is_argument__') |
| |
| def __init__(self, arg, is_argument=True): |
| if not isinstance(arg, str): |
| raise TypeError(f"Forward reference must be a string -- got {arg!r}") |
| |
| # Double-stringified forward references is a result of activating |
| # the 'annotations' future by default. This way, we eliminate them in |
| # the runtime. |
| if arg.startswith(("'", '\"')) and arg.endswith(("'", '"')): |
| arg = arg[1:-1] |
| |
| try: |
| code = compile(arg, '<string>', 'eval') |
| except SyntaxError: |
| raise SyntaxError(f"Forward reference must be an expression -- got {arg!r}") |
| self.__forward_arg__ = arg |
| self.__forward_code__ = code |
| self.__forward_evaluated__ = False |
| self.__forward_value__ = None |
| self.__forward_is_argument__ = is_argument |
| |
| def _evaluate(self, globalns, localns, recursive_guard): |
| if self.__forward_arg__ in recursive_guard: |
| return self |
| if not self.__forward_evaluated__ or localns is not globalns: |
| if globalns is None and localns is None: |
| globalns = localns = {} |
| elif globalns is None: |
| globalns = localns |
| elif localns is None: |
| localns = globalns |
| type_ =_type_check( |
| eval(self.__forward_code__, globalns, localns), |
| "Forward references must evaluate to types.", |
| is_argument=self.__forward_is_argument__, |
| ) |
| self.__forward_value__ = _eval_type( |
| type_, globalns, localns, recursive_guard | {self.__forward_arg__} |
| ) |
| self.__forward_evaluated__ = True |
| return self.__forward_value__ |
| |
| def __eq__(self, other): |
| if not isinstance(other, ForwardRef): |
| return NotImplemented |
| if self.__forward_evaluated__ and other.__forward_evaluated__: |
| return (self.__forward_arg__ == other.__forward_arg__ and |
| self.__forward_value__ == other.__forward_value__) |
| return self.__forward_arg__ == other.__forward_arg__ |
| |
| def __hash__(self): |
| return hash(self.__forward_arg__) |
| |
| def __repr__(self): |
| return f'ForwardRef({self.__forward_arg__!r})' |
| |
| class _TypeVarLike: |
| """Mixin for TypeVar-like types (TypeVar and ParamSpec).""" |
| def __init__(self, bound, covariant, contravariant): |
| """Used to setup TypeVars and ParamSpec's bound, covariant and |
| contravariant attributes. |
| """ |
| if covariant and contravariant: |
| raise ValueError("Bivariant types are not supported.") |
| self.__covariant__ = bool(covariant) |
| self.__contravariant__ = bool(contravariant) |
| if bound: |
| self.__bound__ = _type_check(bound, "Bound must be a type.") |
| else: |
| self.__bound__ = None |
| |
| def __or__(self, right): |
| return Union[self, right] |
| |
| def __ror__(self, right): |
| return Union[self, right] |
| |
| def __repr__(self): |
| if self.__covariant__: |
| prefix = '+' |
| elif self.__contravariant__: |
| prefix = '-' |
| else: |
| prefix = '~' |
| return prefix + self.__name__ |
| |
| def __reduce__(self): |
| return self.__name__ |
| |
| |
| class TypeVar( _Final, _Immutable, _TypeVarLike, _root=True): |
| """Type variable. |
| |
| Usage:: |
| |
| T = TypeVar('T') # Can be anything |
| A = TypeVar('A', str, bytes) # Must be str or bytes |
| |
| Type variables exist primarily for the benefit of static type |
| checkers. They serve as the parameters for generic types as well |
| as for generic function definitions. See class Generic for more |
| information on generic types. Generic functions work as follows: |
| |
| def repeat(x: T, n: int) -> List[T]: |
| '''Return a list containing n references to x.''' |
| return [x]*n |
| |
| def longest(x: A, y: A) -> A: |
| '''Return the longest of two strings.''' |
| return x if len(x) >= len(y) else y |
| |
| The latter example's signature is essentially the overloading |
| of (str, str) -> str and (bytes, bytes) -> bytes. Also note |
| that if the arguments are instances of some subclass of str, |
| the return type is still plain str. |
| |
| At runtime, isinstance(x, T) and issubclass(C, T) will raise TypeError. |
| |
| Type variables defined with covariant=True or contravariant=True |
| can be used to declare covariant or contravariant generic types. |
| See PEP 484 for more details. By default generic types are invariant |
| in all type variables. |
| |
| Type variables can be introspected. e.g.: |
| |
| T.__name__ == 'T' |
| T.__constraints__ == () |
| T.__covariant__ == False |
| T.__contravariant__ = False |
| A.__constraints__ == (str, bytes) |
| |
| Note that only type variables defined in global scope can be pickled. |
| """ |
| |
| __slots__ = ('__name__', '__bound__', '__constraints__', |
| '__covariant__', '__contravariant__', '__dict__') |
| |
| def __init__(self, name, *constraints, bound=None, |
| covariant=False, contravariant=False): |
| self.__name__ = name |
| super().__init__(bound, covariant, contravariant) |
| if constraints and bound is not None: |
| raise TypeError("Constraints cannot be combined with bound=...") |
| if constraints and len(constraints) == 1: |
| raise TypeError("A single constraint is not allowed") |
| msg = "TypeVar(name, constraint, ...): constraints must be types." |
| self.__constraints__ = tuple(_type_check(t, msg) for t in constraints) |
| try: |
| def_mod = sys._getframe(1).f_globals.get('__name__', '__main__') # for pickling |
| except (AttributeError, ValueError): |
| def_mod = None |
| if def_mod != 'typing': |
| self.__module__ = def_mod |
| |
| |
| class ParamSpec(_Final, _Immutable, _TypeVarLike, _root=True): |
| """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``, or as parameters for user-defined |
| Generics. 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. |
| """ |
| |
| __slots__ = ('__name__', '__bound__', '__covariant__', '__contravariant__', |
| '__dict__') |
| |
| args = object() |
| kwargs = object() |
| |
| def __init__(self, name, bound=None, covariant=False, contravariant=False): |
| self.__name__ = name |
| super().__init__(bound, covariant, contravariant) |
| try: |
| def_mod = sys._getframe(1).f_globals.get('__name__', '__main__') |
| except (AttributeError, ValueError): |
| def_mod = None |
| if def_mod != 'typing': |
| self.__module__ = def_mod |
| |
| |
| def _is_dunder(attr): |
| return attr.startswith('__') and attr.endswith('__') |
| |
| class _BaseGenericAlias(_Final, _root=True): |
| """The central part of internal API. |
| |
| This represents a generic version of type 'origin' with type arguments 'params'. |
| There are two kind of these aliases: user defined and special. The special ones |
| are wrappers around builtin collections and ABCs in collections.abc. These must |
| have 'name' always set. If 'inst' is False, then the alias can't be instantiated, |
| this is used by e.g. typing.List and typing.Dict. |
| """ |
| def __init__(self, origin, *, inst=True, name=None): |
| self._inst = inst |
| self._name = name |
| self.__origin__ = origin |
| self.__slots__ = None # This is not documented. |
| |
| def __call__(self, *args, **kwargs): |
| if not self._inst: |
| raise TypeError(f"Type {self._name} cannot be instantiated; " |
| f"use {self.__origin__.__name__}() instead") |
| result = self.__origin__(*args, **kwargs) |
| try: |
| result.__orig_class__ = self |
| except AttributeError: |
| pass |
| return result |
| |
| def __mro_entries__(self, bases): |
| res = [] |
| if self.__origin__ not in bases: |
| res.append(self.__origin__) |
| i = bases.index(self) |
| for b in bases[i+1:]: |
| if isinstance(b, _BaseGenericAlias) or issubclass(b, Generic): |
| break |
| else: |
| res.append(Generic) |
| return tuple(res) |
| |
| def __getattr__(self, attr): |
| # We are careful for copy and pickle. |
| # Also for simplicity we just don't relay all dunder names |
| if '__origin__' in self.__dict__ and not _is_dunder(attr): |
| return getattr(self.__origin__, attr) |
| raise AttributeError(attr) |
| |
| def __setattr__(self, attr, val): |
| if _is_dunder(attr) or attr in ('_name', '_inst', '_nparams'): |
| super().__setattr__(attr, val) |
| else: |
| setattr(self.__origin__, attr, val) |
| |
| def __instancecheck__(self, obj): |
| return self.__subclasscheck__(type(obj)) |
| |
| def __subclasscheck__(self, cls): |
| raise TypeError("Subscripted generics cannot be used with" |
| " class and instance checks") |
| |
| |
| # Special typing constructs Union, Optional, Generic, Callable and Tuple |
| # use three special attributes for internal bookkeeping of generic types: |
| # * __parameters__ is a tuple of unique free type parameters of a generic |
| # type, for example, Dict[T, T].__parameters__ == (T,); |
| # * __origin__ keeps a reference to a type that was subscripted, |
| # e.g., Union[T, int].__origin__ == Union, or the non-generic version of |
| # the type. |
| # * __args__ is a tuple of all arguments used in subscripting, |
| # e.g., Dict[T, int].__args__ == (T, int). |
| |
| |
| class _GenericAlias(_BaseGenericAlias, _root=True): |
| def __init__(self, origin, params, *, inst=True, name=None): |
| super().__init__(origin, inst=inst, name=name) |
| if not isinstance(params, tuple): |
| params = (params,) |
| self.__args__ = tuple(... if a is _TypingEllipsis else |
| () if a is _TypingEmpty else |
| a for a in params) |
| self.__parameters__ = _collect_type_vars(params) |
| if not name: |
| self.__module__ = origin.__module__ |
| |
| def __eq__(self, other): |
| if not isinstance(other, _GenericAlias): |
| return NotImplemented |
| return (self.__origin__ == other.__origin__ |
| and self.__args__ == other.__args__) |
| |
| def __hash__(self): |
| return hash((self.__origin__, self.__args__)) |
| |
| def __or__(self, right): |
| return Union[self, right] |
| |
| def __ror__(self, right): |
| return Union[self, right] |
| |
| @_tp_cache |
| def __getitem__(self, params): |
| if self.__origin__ in (Generic, Protocol): |
| # Can't subscript Generic[...] or Protocol[...]. |
| raise TypeError(f"Cannot subscript already-subscripted {self}") |
| if not isinstance(params, tuple): |
| params = (params,) |
| params = tuple(_type_convert(p) for p in params) |
| if any(isinstance(t, ParamSpec) for t in self.__parameters__): |
| params = _prepare_paramspec_params(self, params) |
| _check_generic(self, params, len(self.__parameters__)) |
| |
| subst = dict(zip(self.__parameters__, params)) |
| new_args = [] |
| for arg in self.__args__: |
| if isinstance(arg, _TypeVarLike): |
| arg = subst[arg] |
| elif isinstance(arg, (_GenericAlias, GenericAlias)): |
| subparams = arg.__parameters__ |
| if subparams: |
| subargs = tuple(subst[x] for x in subparams) |
| arg = arg[subargs] |
| # Required to flatten out the args for CallableGenericAlias |
| if self.__origin__ == collections.abc.Callable and isinstance(arg, tuple): |
| new_args.extend(arg) |
| else: |
| new_args.append(arg) |
| return self.copy_with(tuple(new_args)) |
| |
| def copy_with(self, params): |
| return self.__class__(self.__origin__, params, name=self._name, inst=self._inst) |
| |
| def __repr__(self): |
| if self._name: |
| name = 'typing.' + self._name |
| else: |
| name = _type_repr(self.__origin__) |
| args = ", ".join([_type_repr(a) for a in self.__args__]) |
| return f'{name}[{args}]' |
| |
| def __reduce__(self): |
| if self._name: |
| origin = globals()[self._name] |
| else: |
| origin = self.__origin__ |
| args = tuple(self.__args__) |
| if len(args) == 1 and not isinstance(args[0], tuple): |
| args, = args |
| return operator.getitem, (origin, args) |
| |
| def __mro_entries__(self, bases): |
| if self._name: # generic version of an ABC or built-in class |
| return super().__mro_entries__(bases) |
| if self.__origin__ is Generic: |
| if Protocol in bases: |
| return () |
| i = bases.index(self) |
| for b in bases[i+1:]: |
| if isinstance(b, _BaseGenericAlias) and b is not self: |
| return () |
| return (self.__origin__,) |
| |
| |
| # _nparams is the number of accepted parameters, e.g. 0 for Hashable, |
| # 1 for List and 2 for Dict. It may be -1 if variable number of |
| # parameters are accepted (needs custom __getitem__). |
| |
| class _SpecialGenericAlias(_BaseGenericAlias, _root=True): |
| def __init__(self, origin, nparams, *, inst=True, name=None): |
| if name is None: |
| name = origin.__name__ |
| super().__init__(origin, inst=inst, name=name) |
| self._nparams = nparams |
| if origin.__module__ == 'builtins': |
| self.__doc__ = f'A generic version of {origin.__qualname__}.' |
| else: |
| self.__doc__ = f'A generic version of {origin.__module__}.{origin.__qualname__}.' |
| |
| @_tp_cache |
| def __getitem__(self, params): |
| if not isinstance(params, tuple): |
| params = (params,) |
| msg = "Parameters to generic types must be types." |
| params = tuple(_type_check(p, msg) for p in params) |
| _check_generic(self, params, self._nparams) |
| return self.copy_with(params) |
| |
| def copy_with(self, params): |
| return _GenericAlias(self.__origin__, params, |
| name=self._name, inst=self._inst) |
| |
| def __repr__(self): |
| return 'typing.' + self._name |
| |
| def __subclasscheck__(self, cls): |
| if isinstance(cls, _SpecialGenericAlias): |
| return issubclass(cls.__origin__, self.__origin__) |
| if not isinstance(cls, _GenericAlias): |
| return issubclass(cls, self.__origin__) |
| return super().__subclasscheck__(cls) |
| |
| def __reduce__(self): |
| return self._name |
| |
| def __or__(self, right): |
| return Union[self, right] |
| |
| def __ror__(self, right): |
| return Union[self, right] |
| |
| class _CallableGenericAlias(_GenericAlias, _root=True): |
| def __repr__(self): |
| assert self._name == 'Callable' |
| args = self.__args__ |
| if len(args) == 2 and (args[0] is Ellipsis |
| or isinstance(args[0], (ParamSpec, _ConcatenateGenericAlias))): |
| return super().__repr__() |
| return (f'typing.Callable' |
| f'[[{", ".join([_type_repr(a) for a in args[:-1]])}], ' |
| f'{_type_repr(args[-1])}]') |
| |
| def __reduce__(self): |
| args = self.__args__ |
| if not (len(args) == 2 and (args[0] is Ellipsis |
| or isinstance(args[0], (ParamSpec, _ConcatenateGenericAlias)))): |
| args = list(args[:-1]), args[-1] |
| return operator.getitem, (Callable, args) |
| |
| |
| class _CallableType(_SpecialGenericAlias, _root=True): |
| def copy_with(self, params): |
| return _CallableGenericAlias(self.__origin__, params, |
| name=self._name, inst=self._inst) |
| |
| def __getitem__(self, params): |
| if not isinstance(params, tuple) or len(params) != 2: |
| raise TypeError("Callable must be used as " |
| "Callable[[arg, ...], result].") |
| args, result = params |
| # This relaxes what args can be on purpose to allow things like |
| # PEP 612 ParamSpec. Responsibility for whether a user is using |
| # Callable[...] properly is deferred to static type checkers. |
| if isinstance(args, list): |
| params = (tuple(args), result) |
| else: |
| params = (args, result) |
| return self.__getitem_inner__(params) |
| |
| @_tp_cache |
| def __getitem_inner__(self, params): |
| args, result = params |
| msg = "Callable[args, result]: result must be a type." |
| result = _type_check(result, msg) |
| if args is Ellipsis: |
| return self.copy_with((_TypingEllipsis, result)) |
| if not isinstance(args, tuple): |
| args = (args,) |
| args = tuple(_type_convert(arg) for arg in args) |
| params = args + (result,) |
| return self.copy_with(params) |
| |
| |
| class _TupleType(_SpecialGenericAlias, _root=True): |
| @_tp_cache |
| def __getitem__(self, params): |
| if params == (): |
| return self.copy_with((_TypingEmpty,)) |
| if not isinstance(params, tuple): |
| params = (params,) |
| if len(params) == 2 and params[1] is ...: |
| msg = "Tuple[t, ...]: t must be a type." |
| p = _type_check(params[0], msg) |
| return self.copy_with((p, _TypingEllipsis)) |
| msg = "Tuple[t0, t1, ...]: each t must be a type." |
| params = tuple(_type_check(p, msg) for p in params) |
| return self.copy_with(params) |
| |
| |
| class _UnionGenericAlias(_GenericAlias, _root=True): |
| def copy_with(self, params): |
| return Union[params] |
| |
| def __eq__(self, other): |
| if not isinstance(other, _UnionGenericAlias): |
| return NotImplemented |
| return set(self.__args__) == set(other.__args__) |
| |
| def __hash__(self): |
| return hash(frozenset(self.__args__)) |
| |
| def __repr__(self): |
| args = self.__args__ |
| if len(args) == 2: |
| if args[0] is type(None): |
| return f'typing.Optional[{_type_repr(args[1])}]' |
| elif args[1] is type(None): |
| return f'typing.Optional[{_type_repr(args[0])}]' |
| return super().__repr__() |
| |
| def __instancecheck__(self, obj): |
| return self.__subclasscheck__(type(obj)) |
| |
| def __subclasscheck__(self, cls): |
| for arg in self.__args__: |
| if issubclass(cls, arg): |
| return True |
| |
| |
| def _value_and_type_iter(parameters): |
| return ((p, type(p)) for p in parameters) |
| |
| |
| class _LiteralGenericAlias(_GenericAlias, _root=True): |
| |
| def __eq__(self, other): |
| if not isinstance(other, _LiteralGenericAlias): |
| return NotImplemented |
| |
| return set(_value_and_type_iter(self.__args__)) == set(_value_and_type_iter(other.__args__)) |
| |
| def __hash__(self): |
| return hash(frozenset(_value_and_type_iter(self.__args__))) |
| |
| |
| class _ConcatenateGenericAlias(_GenericAlias, _root=True): |
| pass |
| |
| |
| class Generic: |
| """Abstract base class for generic types. |
| |
| A generic type is typically declared by inheriting from |
| this class parameterized with one or more type variables. |
| For example, a generic mapping type might be defined as:: |
| |
| class Mapping(Generic[KT, VT]): |
| def __getitem__(self, key: KT) -> VT: |
| ... |
| # Etc. |
| |
| This class can then be used as follows:: |
| |
| def lookup_name(mapping: Mapping[KT, VT], key: KT, default: VT) -> VT: |
| try: |
| return mapping[key] |
| except KeyError: |
| return default |
| """ |
| __slots__ = () |
| _is_protocol = False |
| |
| @_tp_cache |
| def __class_getitem__(cls, params): |
| if not isinstance(params, tuple): |
| params = (params,) |
| if not params and cls is not Tuple: |
| raise TypeError( |
| f"Parameter list to {cls.__qualname__}[...] cannot be empty") |
| params = tuple(_type_convert(p) for p in params) |
| if cls in (Generic, Protocol): |
| # Generic and Protocol can only be subscripted with unique type variables. |
| if not all(isinstance(p, _TypeVarLike) for p in params): |
| raise TypeError( |
| f"Parameters to {cls.__name__}[...] must all be type variables " |
| f"or parameter specification variables.") |
| if len(set(params)) != len(params): |
| raise TypeError( |
| f"Parameters to {cls.__name__}[...] must all be unique") |
| else: |
| # Subscripting a regular Generic subclass. |
| if any(isinstance(t, ParamSpec) for t in cls.__parameters__): |
| params = _prepare_paramspec_params(cls, params) |
| _check_generic(cls, params, len(cls.__parameters__)) |
| return _GenericAlias(cls, params) |
| |
| def __init_subclass__(cls, *args, **kwargs): |
| super().__init_subclass__(*args, **kwargs) |
| tvars = [] |
| if '__orig_bases__' in cls.__dict__: |
| error = Generic in cls.__orig_bases__ |
| else: |
| error = Generic in cls.__bases__ and cls.__name__ != 'Protocol' |
| 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]. |
| # 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[...]. |
| gvars = None |
| for base in cls.__orig_bases__: |
| if (isinstance(base, _GenericAlias) and |
| base.__origin__ is Generic): |
| if gvars is not None: |
| raise TypeError( |
| "Cannot inherit from Generic[...] multiple types.") |
| gvars = base.__parameters__ |
| if gvars is not None: |
| tvarset = set(tvars) |
| gvarset = set(gvars) |
| if not tvarset <= gvarset: |
| s_vars = ', '.join(str(t) for t in tvars if t not in gvarset) |
| s_args = ', '.join(str(g) for g in gvars) |
| raise TypeError(f"Some type variables ({s_vars}) are" |
| f" not listed in Generic[{s_args}]") |
| tvars = gvars |
| cls.__parameters__ = tuple(tvars) |
| |
| |
| class _TypingEmpty: |
| """Internal placeholder for () or []. Used by TupleMeta and CallableMeta |
| to allow empty list/tuple in specific places, without allowing them |
| to sneak in where prohibited. |
| """ |
| |
| |
| class _TypingEllipsis: |
| """Internal placeholder for ... (ellipsis).""" |
| |
| |
| _TYPING_INTERNALS = ['__parameters__', '__orig_bases__', '__orig_class__', |
| '_is_protocol', '_is_runtime_protocol'] |
| |
| _SPECIAL_NAMES = ['__abstractmethods__', '__annotations__', '__dict__', '__doc__', |
| '__init__', '__module__', '__new__', '__slots__', |
| '__subclasshook__', '__weakref__', '__class_getitem__'] |
| |
| # These special attributes will be not collected as protocol members. |
| EXCLUDED_ATTRIBUTES = _TYPING_INTERNALS + _SPECIAL_NAMES + ['_MutableMapping__marker'] |
| |
| |
| def _get_protocol_attrs(cls): |
| """Collect protocol members from a protocol class objects. |
| |
| This includes names actually defined in the class dictionary, as well |
| as names that appear in annotations. Special names (above) are skipped. |
| """ |
| 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 EXCLUDED_ATTRIBUTES: |
| attrs.add(attr) |
| return attrs |
| |
| |
| def _is_callable_members_only(cls): |
| # PEP 544 prohibits using issubclass() with protocols that have non-method members. |
| return all(callable(getattr(cls, attr, None)) for attr in _get_protocol_attrs(cls)) |
| |
| |
| def _no_init(self, *args, **kwargs): |
| if type(self)._is_protocol: |
| raise TypeError('Protocols cannot be instantiated') |
| |
| |
| def _allow_reckless_class_checks(): |
| """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. |
| """ |
| try: |
| return sys._getframe(3).f_globals['__name__'] in ['abc', 'functools'] |
| except (AttributeError, ValueError): # For platforms without _getframe(). |
| return True |
| |
| |
| _PROTO_ALLOWLIST = { |
| 'collections.abc': [ |
| 'Callable', 'Awaitable', 'Iterable', 'Iterator', 'AsyncIterable', |
| 'Hashable', 'Sized', 'Container', 'Collection', 'Reversible', |
| ], |
| 'contextlib': ['AbstractContextManager', 'AbstractAsyncContextManager'], |
| } |
| |
| |
| class _ProtocolMeta(ABCMeta): |
| # This metaclass is really 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 |
| # All *methods* can be blocked by setting them to None. |
| (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(Generic, 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.runtime_checkable act as simple-minded runtime protocols that check |
| 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 |
| _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. |
| def _proto_hook(other): |
| if not cls.__dict__.get('_is_protocol', False): |
| return NotImplemented |
| |
| # First, perform various sanity checks. |
| if not getattr(cls, '_is_runtime_protocol', False): |
| if _allow_reckless_class_checks(): |
| return NotImplemented |
| raise TypeError("Instance and class checks can only be used with" |
| " @runtime_checkable protocols") |
| if not _is_callable_members_only(cls): |
| if _allow_reckless_class_checks(): |
| return NotImplemented |
| raise TypeError("Protocols with non-method members" |
| " don't support issubclass()") |
| if not isinstance(other, type): |
| # Same error message as for issubclass(1, int). |
| raise TypeError('issubclass() arg 1 must be a class') |
| |
| # Second, perform the actual structural compatibility check. |
| for attr in _get_protocol_attrs(cls): |
| 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 |
| issubclass(other, Generic) 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 |
| |
| # ... otherwise check consistency of bases, and prohibit instantiation. |
| for base in cls.__bases__: |
| if not (base in (object, Generic) or |
| base.__module__ in _PROTO_ALLOWLIST and |
| base.__name__ in _PROTO_ALLOWLIST[base.__module__] or |
| issubclass(base, Generic) and base._is_protocol): |
| raise TypeError('Protocols can only inherit from other' |
| ' protocols, got %r' % base) |
| cls.__init__ = _no_init |
| |
| |
| class _AnnotatedAlias(_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.Annotated[{}, {}]".format( |
| _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 |
| return (self.__origin__ == other.__origin__ |
| and 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. |
| |
| 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 = _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 runtime_checkable(cls): |
| """Mark a protocol class as a runtime protocol. |
| |
| Such protocol 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 |
| one trick ponies in collections.abc such as Iterable. |
| For example:: |
| |
| @runtime_checkable |
| class Closable(Protocol): |
| def close(self): ... |
| |
| assert isinstance(open('/some/file'), Closable) |
| |
| Warning: this will check only the presence of the required methods, |
| not their type signatures! |
| """ |
| if not issubclass(cls, Generic) 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 |
| |
| |
| def cast(typ, val): |
| """Cast a value to a type. |
| |
| This returns the value unchanged. To the type checker this |
| signals that the return value has the designated type, but at |
| runtime we intentionally don't check anything (we want this |
| to be as fast as possible). |
| """ |
| return val |
| |
| |
| def _get_defaults(func): |
| """Internal helper to extract the default arguments, by name.""" |
| try: |
| code = func.__code__ |
| except AttributeError: |
| # Some built-in functions don't have __code__, __defaults__, etc. |
| return {} |
| pos_count = code.co_argcount |
| arg_names = code.co_varnames |
| arg_names = arg_names[:pos_count] |
| defaults = func.__defaults__ or () |
| kwdefaults = func.__kwdefaults__ |
| res = dict(kwdefaults) if kwdefaults else {} |
| pos_offset = pos_count - len(defaults) |
| for name, value in zip(arg_names[pos_offset:], defaults): |
| assert name not in res |
| res[name] = value |
| return res |
| |
| |
| _allowed_types = (types.FunctionType, types.BuiltinFunctionType, |
| types.MethodType, types.ModuleType, |
| WrapperDescriptorType, MethodWrapperType, MethodDescriptorType) |
| |
| |
| 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. |
| """ |
| |
| if getattr(obj, '__no_type_check__', None): |
| return {} |
| # Classes require a special treatment. |
| if isinstance(obj, type): |
| hints = {} |
| for base in reversed(obj.__mro__): |
| if globalns is None: |
| base_globals = sys.modules[base.__module__].__dict__ |
| else: |
| base_globals = globalns |
| ann = base.__dict__.get('__annotations__', {}) |
| for name, value in ann.items(): |
| if value is None: |
| value = type(None) |
| if isinstance(value, str): |
| value = ForwardRef(value, is_argument=False) |
| value = _eval_type(value, base_globals, localns) |
| hints[name] = value |
| return hints if include_extras else {k: _strip_annotations(t) for k, t in hints.items()} |
| |
| if globalns is None: |
| if isinstance(obj, types.ModuleType): |
| globalns = obj.__dict__ |
| else: |
| nsobj = obj |
| # Find globalns for the unwrapped object. |
| while hasattr(nsobj, '__wrapped__'): |
| nsobj = nsobj.__wrapped__ |
| globalns = getattr(nsobj, '__globals__', {}) |
| if localns is None: |
| localns = globalns |
| elif localns is None: |
| localns = globalns |
| hints = getattr(obj, '__annotations__', None) |
| if hints is None: |
| # Return empty annotations for something that _could_ have them. |
| if isinstance(obj, _allowed_types): |
| return {} |
| else: |
| raise TypeError('{!r} is not a module, class, method, ' |
| 'or function.'.format(obj)) |
| defaults = _get_defaults(obj) |
| hints = dict(hints) |
| for name, value in hints.items(): |
| if value is None: |
| value = type(None) |
| if isinstance(value, str): |
| value = ForwardRef(value) |
| value = _eval_type(value, globalns, localns) |
| if name in defaults and defaults[name] is None: |
| value = Optional[value] |
| hints[name] = value |
| return hints if include_extras else {k: _strip_annotations(t) for k, t in hints.items()} |
| |
| |
| def _strip_annotations(t): |
| """Strips the annotations from a given type. |
| """ |
| if isinstance(t, _AnnotatedAlias): |
| return _strip_annotations(t.__origin__) |
| if isinstance(t, _GenericAlias): |
| stripped_args = tuple(_strip_annotations(a) for a in t.__args__) |
| if stripped_args == t.__args__: |
| return t |
| return t.copy_with(stripped_args) |
| if isinstance(t, GenericAlias): |
| stripped_args = tuple(_strip_annotations(a) for a in t.__args__) |
| if stripped_args == t.__args__: |
| return t |
| return GenericAlias(t.__origin__, stripped_args) |
| return t |
| |
| |
| 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, (_BaseGenericAlias, GenericAlias)): |
| return tp.__origin__ |
| if tp is Generic: |
| return Generic |
| if isinstance(tp, types.Union): |
| return types.Union |
| 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, GenericAlias)): |
| res = tp.__args__ |
| if (tp.__origin__ is collections.abc.Callable |
| and not (res[0] is Ellipsis |
| or isinstance(res[0], (ParamSpec, _ConcatenateGenericAlias)))): |
| res = (list(res[:-1]), res[-1]) |
| return res |
| if isinstance(tp, types.Union): |
| return tp.__args__ |
| return () |
| |
| |
| 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 |
| """ |
| return isinstance(tp, _TypedDictMeta) |
| |
| |
| def no_type_check(arg): |
| """Decorator to indicate that annotations are not type hints. |
| |
| The argument must be a class or function; if it is a class, it |
| applies recursively to all methods and classes defined in that class |
| (but not to methods defined in its superclasses or subclasses). |
| |
| This mutates the function(s) or class(es) in place. |
| """ |
| if isinstance(arg, type): |
| arg_attrs = arg.__dict__.copy() |
| for attr, val in arg.__dict__.items(): |
| if val in arg.__bases__ + (arg,): |
| arg_attrs.pop(attr) |
| for obj in arg_attrs.values(): |
| if isinstance(obj, types.FunctionType): |
| obj.__no_type_check__ = True |
| if isinstance(obj, type): |
| no_type_check(obj) |
| try: |
| arg.__no_type_check__ = True |
| except TypeError: # built-in classes |
| pass |
| return arg |
| |
| |
| def no_type_check_decorator(decorator): |
| """Decorator to give another decorator the @no_type_check effect. |
| |
| This wraps the decorator with something that wraps the decorated |
| function in @no_type_check. |
| """ |
| |
| @functools.wraps(decorator) |
| def wrapped_decorator(*args, **kwds): |
| func = decorator(*args, **kwds) |
| func = no_type_check(func) |
| return func |
| |
| return wrapped_decorator |
| |
| |
| 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 |
| |
| |
| def final(f): |
| """A decorator to indicate final methods and final classes. |
| |
| Use this decorator 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 |
| |
| |
| # Some unconstrained type variables. These are used by the container types. |
| # (These are not for export.) |
| T = TypeVar('T') # Any type. |
| KT = TypeVar('KT') # Key type. |
| VT = TypeVar('VT') # Value type. |
| T_co = TypeVar('T_co', covariant=True) # Any type covariant containers. |
| V_co = TypeVar('V_co', covariant=True) # Any type covariant containers. |
| VT_co = TypeVar('VT_co', covariant=True) # Value type covariant containers. |
| T_contra = TypeVar('T_contra', contravariant=True) # Ditto contravariant. |
| # Internal type variable used for Type[]. |
| CT_co = TypeVar('CT_co', covariant=True, bound=type) |
| |
| # A useful type variable with constraints. This represents string types. |
| # (This one *is* for export!) |
| AnyStr = TypeVar('AnyStr', bytes, str) |
| |
| |
| # Various ABCs mimicking those in collections.abc. |
| _alias = _SpecialGenericAlias |
| |
| Hashable = _alias(collections.abc.Hashable, 0) # Not generic. |
| Awaitable = _alias(collections.abc.Awaitable, 1) |
| Coroutine = _alias(collections.abc.Coroutine, 3) |
| AsyncIterable = _alias(collections.abc.AsyncIterable, 1) |
| AsyncIterator = _alias(collections.abc.AsyncIterator, 1) |
| Iterable = _alias(collections.abc.Iterable, 1) |
| Iterator = _alias(collections.abc.Iterator, 1) |
| Reversible = _alias(collections.abc.Reversible, 1) |
| Sized = _alias(collections.abc.Sized, 0) # Not generic. |
| Container = _alias(collections.abc.Container, 1) |
| Collection = _alias(collections.abc.Collection, 1) |
| Callable = _CallableType(collections.abc.Callable, 2) |
| Callable.__doc__ = \ |
| """Callable type; Callable[[int], str] is a function of (int) -> str. |
| |
| The subscription syntax must always be used with exactly two |
| values: the argument list and the return type. The argument list |
| must be a list of types or ellipsis; the return type must be a single type. |
| |
| There is no syntax to indicate optional or keyword arguments, |
| such function types are rarely used as callback types. |
| """ |
| AbstractSet = _alias(collections.abc.Set, 1, name='AbstractSet') |
| MutableSet = _alias(collections.abc.MutableSet, 1) |
| # NOTE: Mapping is only covariant in the value type. |
| Mapping = _alias(collections.abc.Mapping, 2) |
| MutableMapping = _alias(collections.abc.MutableMapping, 2) |
| Sequence = _alias(collections.abc.Sequence, 1) |
| MutableSequence = _alias(collections.abc.MutableSequence, 1) |
| ByteString = _alias(collections.abc.ByteString, 0) # Not generic |
| # Tuple accepts variable number of parameters. |
| Tuple = _TupleType(tuple, -1, inst=False, name='Tuple') |
| Tuple.__doc__ = \ |
| """Tuple type; Tuple[X, Y] is the cross-product type of X and Y. |
| |
| Example: Tuple[T1, T2] is a tuple of two elements corresponding |
| to type variables T1 and T2. Tuple[int, float, str] is a tuple |
| of an int, a float and a string. |
| |
| To specify a variable-length tuple of homogeneous type, use Tuple[T, ...]. |
| """ |
| List = _alias(list, 1, inst=False, name='List') |
| Deque = _alias(collections.deque, 1, name='Deque') |
| Set = _alias(set, 1, inst=False, name='Set') |
| FrozenSet = _alias(frozenset, 1, inst=False, name='FrozenSet') |
| MappingView = _alias(collections.abc.MappingView, 1) |
| KeysView = _alias(collections.abc.KeysView, 1) |
| ItemsView = _alias(collections.abc.ItemsView, 2) |
| ValuesView = _alias(collections.abc.ValuesView, 1) |
| ContextManager = _alias(contextlib.AbstractContextManager, 1, name='ContextManager') |
| AsyncContextManager = _alias(contextlib.AbstractAsyncContextManager, 1, name='AsyncContextManager') |
| Dict = _alias(dict, 2, inst=False, name='Dict') |
| DefaultDict = _alias(collections.defaultdict, 2, name='DefaultDict') |
| OrderedDict = _alias(collections.OrderedDict, 2) |
| Counter = _alias(collections.Counter, 1) |
| ChainMap = _alias(collections.ChainMap, 2) |
| Generator = _alias(collections.abc.Generator, 3) |
| AsyncGenerator = _alias(collections.abc.AsyncGenerator, 2) |
| Type = _alias(type, 1, inst=False, name='Type') |
| Type.__doc__ = \ |
| """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. |
| """ |
| |
| |
| @runtime_checkable |
| class SupportsInt(Protocol): |
| """An ABC with one abstract method __int__.""" |
| __slots__ = () |
| |
| @abstractmethod |
| def __int__(self) -> int: |
| pass |
| |
| |
| @runtime_checkable |
| class SupportsFloat(Protocol): |
| """An ABC with one abstract method __float__.""" |
| __slots__ = () |
| |
| @abstractmethod |
| def __float__(self) -> float: |
| pass |
| |
| |
| @runtime_checkable |
| class SupportsComplex(Protocol): |
| """An ABC with one abstract method __complex__.""" |
| __slots__ = () |
| |
| @abstractmethod |
| def __complex__(self) -> complex: |
| pass |
| |
| |
| @runtime_checkable |
| class SupportsBytes(Protocol): |
| """An ABC with one abstract method __bytes__.""" |
| __slots__ = () |
| |
| @abstractmethod |
| def __bytes__(self) -> bytes: |
| pass |
| |
| |
| @runtime_checkable |
| class SupportsIndex(Protocol): |
| """An ABC with one abstract method __index__.""" |
| __slots__ = () |
| |
| @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__ = () |
| |
| @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__ = () |
| |
| @abstractmethod |
| def __round__(self, ndigits: int = 0) -> T_co: |
| pass |
| |
| |
| def _make_nmtuple(name, types, module, defaults = ()): |
| fields = [n for n, t in types] |
| types = {n: _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__ = types |
| return nm_tpl |
| |
| |
| # attributes prohibited to set in NamedTuple class syntax |
| _prohibited = frozenset({'__new__', '__init__', '__slots__', '__getnewargs__', |
| '_fields', '_field_defaults', |
| '_make', '_replace', '_asdict', '_source'}) |
| |
| _special = frozenset({'__module__', '__name__', '__annotations__'}) |
| |
| |
| class NamedTupleMeta(type): |
| |
| def __new__(cls, typename, bases, ns): |
| assert bases[0] is _NamedTuple |
| 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__']) |
| # update from user namespace without overriding special namedtuple attributes |
| for key in ns: |
| if key in _prohibited: |
| raise AttributeError("Cannot overwrite NamedTuple attribute " + key) |
| elif key not in _special and key not in nm_tpl._fields: |
| setattr(nm_tpl, key, ns[key]) |
| return nm_tpl |
| |
| |
| def NamedTuple(typename, fields=None, /, **kwargs): |
| """Typed version of namedtuple. |
| |
| Usage in Python versions >= 3.6:: |
| |
| 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.) |
| Alternative equivalent keyword syntax is also accepted:: |
| |
| Employee = NamedTuple('Employee', name=str, id=int) |
| |
| In Python versions <= 3.5 use:: |
| |
| Employee = NamedTuple('Employee', [('name', str), ('id', int)]) |
| """ |
| if fields is None: |
| fields = kwargs.items() |
| elif kwargs: |
| raise TypeError("Either list of fields or keywords" |
| " can be provided to NamedTuple, not both") |
| try: |
| module = sys._getframe(1).f_globals.get('__name__', '__main__') |
| except (AttributeError, ValueError): |
| module = None |
| return _make_nmtuple(typename, fields, module=module) |
| |
| _NamedTuple = type.__new__(NamedTupleMeta, 'NamedTuple', (), {}) |
| |
| def _namedtuple_mro_entries(bases): |
| if len(bases) > 1: |
| raise TypeError("Multiple inheritance with NamedTuple is not supported") |
| assert bases[0] is NamedTuple |
| return (_NamedTuple,) |
| |
| NamedTuple.__mro_entries__ = _namedtuple_mro_entries |
| |
| |
| 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: |
| raise TypeError('cannot inherit from both a TypedDict type ' |
| 'and a non-TypedDict base class') |
| tp_dict = type.__new__(_TypedDictMeta, 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: _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 |
| |
| __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__ |
| |
| |
| def TypedDict(typename, fields=None, /, *, total=True, **kwargs): |
| """A simple typed namespace. 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, where each key is |
| 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}) |
| |
| By default, all keys must be present in a TypedDict. It is possible |
| to override this by specifying totality. |
| Usage:: |
| |
| 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 class syntax is only supported in Python 3.6+, while two other |
| syntax forms work for Python 2.7 and 3.2+ |
| """ |
| 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)} |
| 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, total=total) |
| |
| _TypedDict = type.__new__(_TypedDictMeta, 'TypedDict', (), {}) |
| TypedDict.__mro_entries__ = lambda bases: (_TypedDict,) |
| |
| |
| 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 |
| |
| |
| # Python-version-specific alias (Python 2: unicode; Python 3: str) |
| Text = str |
| |
| |
| # Constant that's True when type checking, but False here. |
| TYPE_CHECKING = False |
| |
| |
| class IO(Generic[AnyStr]): |
| """Generic base class for TextIO and BinaryIO. |
| |
| This is an abstract, generic version of the return of open(). |
| |
| NOTE: This does not distinguish between the different possible |
| classes (text vs. binary, read vs. write vs. read/write, |
| append-only, unbuffered). The TextIO and BinaryIO subclasses |
| below capture the distinctions between text vs. binary, which is |
| pervasive in the interface; however we currently do not offer a |
| way to track the other distinctions in the type system. |
| """ |
| |
| __slots__ = () |
| |
| @property |
| @abstractmethod |
| def mode(self) -> str: |
| pass |
| |
| @property |
| @abstractmethod |
| def name(self) -> str: |
| pass |
| |
| @abstractmethod |
| def close(self) -> None: |
| pass |
| |
| @property |
| @abstractmethod |
| def closed(self) -> bool: |
| pass |
| |
| @abstractmethod |
| def fileno(self) -> int: |
| pass |
| |
| @abstractmethod |
| def flush(self) -> None: |
| pass |
| |
| @abstractmethod |
| def isatty(self) -> bool: |
| pass |
| |
| @abstractmethod |
| def read(self, n: int = -1) -> AnyStr: |
| pass |
| |
| @abstractmethod |
| def readable(self) -> bool: |
| pass |
| |
| @abstractmethod |
| def readline(self, limit: int = -1) -> AnyStr: |
| pass |
| |
| @abstractmethod |
| def readlines(self, hint: int = -1) -> List[AnyStr]: |
| pass |
| |
| @abstractmethod |
| def seek(self, offset: int, whence: int = 0) -> int: |
| pass |
| |
| @abstractmethod |
| def seekable(self) -> bool: |
| pass |
| |
| @abstractmethod |
| def tell(self) -> int: |
| pass |
| |
| @abstractmethod |
| def truncate(self, size: int = None) -> int: |
| pass |
| |
| @abstractmethod |
| def writable(self) -> bool: |
| pass |
| |
| @abstractmethod |
| def write(self, s: AnyStr) -> int: |
| pass |
| |
| @abstractmethod |
| def writelines(self, lines: List[AnyStr]) -> None: |
| pass |
| |
| @abstractmethod |
| def __enter__(self) -> 'IO[AnyStr]': |
| pass |
| |
| @abstractmethod |
| def __exit__(self, type, value, traceback) -> None: |
| pass |
| |
| |
| class BinaryIO(IO[bytes]): |
| """Typed version of the return of open() in binary mode.""" |
| |
| __slots__ = () |
| |
| @abstractmethod |
| def write(self, s: Union[bytes, bytearray]) -> int: |
| pass |
| |
| @abstractmethod |
| def __enter__(self) -> 'BinaryIO': |
| pass |
| |
| |
| class TextIO(IO[str]): |
| """Typed version of the return of open() in text mode.""" |
| |
| __slots__ = () |
| |
| @property |
| @abstractmethod |
| def buffer(self) -> BinaryIO: |
| pass |
| |
| @property |
| @abstractmethod |
| def encoding(self) -> str: |
| pass |
| |
| @property |
| @abstractmethod |
| def errors(self) -> Optional[str]: |
| pass |
| |
| @property |
| @abstractmethod |
| def line_buffering(self) -> bool: |
| pass |
| |
| @property |
| @abstractmethod |
| def newlines(self) -> Any: |
| pass |
| |
| @abstractmethod |
| def __enter__(self) -> 'TextIO': |
| pass |
| |
| |
| class io: |
| """Wrapper namespace for IO generic classes.""" |
| |
| __all__ = ['IO', 'TextIO', 'BinaryIO'] |
| IO = IO |
| TextIO = TextIO |
| BinaryIO = BinaryIO |
| |
| |
| io.__name__ = __name__ + '.io' |
| sys.modules[io.__name__] = io |
| |
| Pattern = _alias(stdlib_re.Pattern, 1) |
| Match = _alias(stdlib_re.Match, 1) |
| |
| class re: |
| """Wrapper namespace for re type aliases.""" |
| |
| __all__ = ['Pattern', 'Match'] |
| Pattern = Pattern |
| Match = Match |
| |
| |
| re.__name__ = __name__ + '.re' |
| sys.modules[re.__name__] = re |