"""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* Two classes whose instances can be type arguments in addition to types: ForwardRef and TypeVar* 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."""fromabcimportabstractmethod,ABCMetaimportcollectionsimportcollections.abcimportcontextlibimportfunctoolsimportoperatorimportreasstdlib_re# Avoid confusion with the re we export.importsysimporttypesfromtypesimportWrapperDescriptorType,MethodWrapperType,MethodDescriptorType,GenericAlias# Please keep __all__ alphabetized within each category.__all__=[# Super-special typing primitives.'Annotated','Any','Callable','ClassVar','Final','ForwardRef','Generic','Literal','Optional','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',# Other concrete types.'BinaryIO','IO','Match','Pattern','TextIO',# One-off things.'AnyStr','cast','final','get_args','get_origin','get_type_hints','NewType','no_type_check','no_type_check_decorator','NoReturn','overload','runtime_checkable','Text','TYPE_CHECKING',]# 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,module=None,*,allow_special_forms=False):"""For converting None to type(None), and strings to ForwardRef."""ifargisNone:returntype(None)ifisinstance(arg,str):returnForwardRef(arg,module=module,is_class=allow_special_forms)returnargdef_type_check(arg,msg,is_argument=True,module=None,*,allow_special_forms=False):"""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)ifnotallow_special_forms:invalid_generic_forms+=(ClassVar,)ifis_argument:invalid_generic_forms+=(Final,)arg=_type_convert(arg,module=module,allow_special_forms=allow_special_forms)if(isinstance(arg,_GenericAlias)andarg.__origin__ininvalid_generic_forms):raiseTypeError(f"{arg} is not valid as type argument")ifargin(Any,NoReturn,Final):returnargifisinstance(arg,_SpecialForm)orargin(Generic,Protocol):raiseTypeError(f"Plain {arg} is not valid as type argument")ifisinstance(arg,(type,TypeVar,ForwardRef)):returnargifnotcallable(arg):raiseTypeError(f"{msg} Got {arg!r:.100}.")returnargdef_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). """ifisinstance(obj,types.GenericAlias):returnrepr(obj)ifisinstance(obj,type):ifobj.__module__=='builtins':returnobj.__qualname__returnf'{obj.__module__}.{obj.__qualname__}'ifobjis...:return('...')ifisinstance(obj,types.FunctionType):returnobj.__name__returnrepr(obj)def_collect_type_vars(types):"""Collect all type variable contained in types in order of first appearance (lexicographic order). For example:: _collect_type_vars((T, List[S, T])) == (T, S) """tvars=[]fortintypes:ifisinstance(t,TypeVar)andtnotintvars:tvars.append(t)ifisinstance(t,(_GenericAlias,GenericAlias)):tvars.extend([tfortint.__parameters__iftnotintvars])returntuple(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. """ifnotelen:raiseTypeError(f"{cls} is not a generic class")alen=len(parameters)ifalen!=elen:raiseTypeError(f"Too {'many'ifalen>elenelse'few'} parameters for {cls};"f" actual {alen}, expected {elen}")def_deduplicate(params):# Weed out strict duplicates, preserving the first of each occurrence.all_params=set(params)iflen(all_params)<len(params):new_params=[]fortinparams:iftinall_params:new_params.append(t)all_params.remove(t)params=new_paramsassertnotall_params,all_paramsreturnparamsdef_remove_dups_flatten(parameters):"""An internal helper for Union creation and substitution: flatten Unions among parameters, then remove duplicates. """# Flatten out Union[Union[...], ...].params=[]forpinparameters:ifisinstance(p,_UnionGenericAlias):params.extend(p.__args__)elifisinstance(p,tuple)andlen(p)>0andp[0]isUnion:params.extend(p[1:])else:params.append(p)returntuple(_deduplicate(params))def_flatten_literal_params(parameters):"""An internal helper for Literal creation: flatten Literals among parameters"""params=[]forpinparameters:ifisinstance(p,_LiteralGenericAlias):params.extend(p.__args__)else:params.append(p)returntuple(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. """defdecorator(func):cached=functools.lru_cache(typed=typed)(func)_cleanups.append(cached.cache_clear)@functools.wraps(func)definner(*args,**kwds):try:returncached(*args,**kwds)exceptTypeError:pass# All real errors (not unhashable args) are raised below.returnfunc(*args,**kwds)returninneriffuncisnotNone:returndecorator(func)returndecoratordef_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 infinite recursion with a recursive ForwardRef. """ifisinstance(t,ForwardRef):returnt._evaluate(globalns,localns,recursive_guard)ifisinstance(t,(_GenericAlias,GenericAlias)):ev_args=tuple(_eval_type(a,globalns,localns,recursive_guard)foraint.__args__)ifev_args==t.__args__:returntifisinstance(t,GenericAlias):returnGenericAlias(t.__origin__,ev_args)else:returnt.copy_with(ev_args)returntclass_Final:"""Mixin to prohibit subclassing"""__slots__=('__weakref__',)def__init_subclass__(self,/,*args,**kwds):if'_root'notinkwds:raiseTypeError("Cannot subclass special typing classes")class_Immutable:"""Mixin to indicate that object should not be copied."""__slots__=()def__copy__(self):returnselfdef__deepcopy__(self,memo):returnself# 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=getitemself._name=getitem.__name__self.__doc__=getitem.__doc__def__mro_entries__(self,bases):raiseTypeError(f"Cannot subclass {self!r}")def__repr__(self):return'typing.'+self._namedef__reduce__(self):returnself._namedef__call__(self,*args,**kwds):raiseTypeError(f"Cannot instantiate {self!r}")def__instancecheck__(self,obj):raiseTypeError(f"{self} cannot be used with isinstance()")def__subclasscheck__(self,cls):raiseTypeError(f"{self} cannot be used with issubclass()")@_tp_cachedef__getitem__(self,parameters):returnself._getitem(self,parameters)class_LiteralSpecialForm(_SpecialForm,_root=True):def__getitem__(self,parameters):ifnotisinstance(parameters,tuple):parameters=(parameters,)returnself._getitem(self,*parameters)@_SpecialFormdefAny(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. """raiseTypeError(f"{self} is not subscriptable")@_SpecialFormdefNoReturn(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. """raiseTypeError(f"{self} is not subscriptable")@_SpecialFormdefClassVar(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,))@_SpecialFormdefFinal(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,))@_SpecialFormdefUnion(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]. """ifparameters==():raiseTypeError("Cannot take a Union of no types.")ifnotisinstance(parameters,tuple):parameters=(parameters,)msg="Union[arg, ...]: each arg must be a type."parameters=tuple(_type_check(p,msg)forpinparameters)parameters=_remove_dups_flatten(parameters)iflen(parameters)==1:returnparameters[0]return_UnionGenericAlias(self,parameters)@_SpecialFormdefOptional(self,parameters):"""Optional type. Optional[X] is equivalent to Union[X, None]. """arg=_type_check(parameters,f"{self} requires a single type.")returnUnion[arg,type(None)]@_LiteralSpecialForm@_tp_cache(typed=True)defLiteral(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.parameters=_flatten_literal_params(parameters)try:parameters=tuple(pforp,_in_deduplicate(list(_value_and_type_iter(parameters))))exceptTypeError:# unhashable parameterspassreturn_LiteralGenericAlias(self,parameters)classForwardRef(_Final,_root=True):"""Internal wrapper to hold a forward reference."""__slots__=('__forward_arg__','__forward_code__','__forward_evaluated__','__forward_value__','__forward_is_argument__','__forward_is_class__','__forward_module__')def__init__(self,arg,is_argument=True,module=None,*,is_class=False):ifnotisinstance(arg,str):raiseTypeError(f"Forward reference must be a string -- got {arg!r}")try:code=compile(arg,'<string>','eval')exceptSyntaxError:raiseSyntaxError(f"Forward reference must be an expression -- got {arg!r}")self.__forward_arg__=argself.__forward_code__=codeself.__forward_evaluated__=Falseself.__forward_value__=Noneself.__forward_is_argument__=is_argumentself.__forward_is_class__=is_classself.__forward_module__=moduledef_evaluate(self,globalns,localns,recursive_guard):ifself.__forward_arg__inrecursive_guard:returnselfifnotself.__forward_evaluated__orlocalnsisnotglobalns:ifglobalnsisNoneandlocalnsisNone:globalns=localns={}elifglobalnsisNone:globalns=localnseliflocalnsisNone:localns=globalnsifself.__forward_module__isnotNone:globalns=getattr(sys.modules.get(self.__forward_module__,None),'__dict__',globalns)type_=_type_check(eval(self.__forward_code__,globalns,localns),"Forward references must evaluate to types.",is_argument=self.__forward_is_argument__,allow_special_forms=self.__forward_is_class__,)self.__forward_value__=_eval_type(type_,globalns,localns,recursive_guard|{self.__forward_arg__})self.__forward_evaluated__=Truereturnself.__forward_value__def__eq__(self,other):ifnotisinstance(other,ForwardRef):returnNotImplementedifself.__forward_evaluated__andother.__forward_evaluated__:return(self.__forward_arg__==other.__forward_arg__andself.__forward_value__==other.__forward_value__)return(self.__forward_arg__==other.__forward_arg__andself.__forward_module__==other.__forward_module__)def__hash__(self):returnhash((self.__forward_arg__,self.__forward_module__))def__repr__(self):returnf'ForwardRef({self.__forward_arg__!r})'classTypeVar(_Final,_Immutable,_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__=nameifcovariantandcontravariant:raiseValueError("Bivariant types are not supported.")self.__covariant__=bool(covariant)self.__contravariant__=bool(contravariant)ifconstraintsandboundisnotNone:raiseTypeError("Constraints cannot be combined with bound=...")ifconstraintsandlen(constraints)==1:raiseTypeError("A single constraint is not allowed")msg="TypeVar(name, constraint, ...): constraints must be types."self.__constraints__=tuple(_type_check(t,msg)fortinconstraints)ifbound:self.__bound__=_type_check(bound,"Bound must be a type.")else:self.__bound__=Nonetry:def_mod=sys._getframe(1).f_globals.get('__name__','__main__')# for picklingexcept(AttributeError,ValueError):def_mod=Noneifdef_mod!='typing':self.__module__=def_moddef__repr__(self):ifself.__covariant__:prefix='+'elifself.__contravariant__:prefix='-'else:prefix='~'returnprefix+self.__name__def__reduce__(self):returnself.__name__def_is_dunder(attr):returnattr.startswith('__')andattr.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=instself._name=nameself.__origin__=originself.__slots__=None# This is not documented.def__call__(self,*args,**kwargs):ifnotself._inst:raiseTypeError(f"Type {self._name} cannot be instantiated; "f"use {self.__origin__.__name__}() instead")result=self.__origin__(*args,**kwargs)try:result.__orig_class__=selfexceptAttributeError:passreturnresultdef__mro_entries__(self,bases):res=[]ifself.__origin__notinbases:res.append(self.__origin__)i=bases.index(self)forbinbases[i+1:]:ifisinstance(b,_BaseGenericAlias)orissubclass(b,Generic):breakelse:res.append(Generic)returntuple(res)def__getattr__(self,attr):# We are careful for copy and pickle.# Also for simplicity we don't relay any dunder namesif'__origin__'inself.__dict__andnot_is_dunder(attr):returngetattr(self.__origin__,attr)raiseAttributeError(attr)def__setattr__(self,attr,val):if_is_dunder(attr)orattrin('_name','_inst','_nparams'):super().__setattr__(attr,val)else:setattr(self.__origin__,attr,val)def__instancecheck__(self,obj):returnself.__subclasscheck__(type(obj))def__subclasscheck__(self,cls):raiseTypeError("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)ifnotisinstance(params,tuple):params=(params,)self.__args__=tuple(...ifais_TypingEllipsiselse()ifais_TypingEmptyelseaforainparams)self.__parameters__=_collect_type_vars(params)ifnotname:self.__module__=origin.__module__def__eq__(self,other):ifnotisinstance(other,_GenericAlias):returnNotImplementedreturn(self.__origin__==other.__origin__andself.__args__==other.__args__)def__hash__(self):returnhash((self.__origin__,self.__args__))@_tp_cachedef__getitem__(self,params):ifself.__origin__in(Generic,Protocol):# Can't subscript Generic[...] or Protocol[...].raiseTypeError(f"Cannot subscript already-subscripted {self}")ifnotisinstance(params,tuple):params=(params,)msg="Parameters to generic types must be types."params=tuple(_type_check(p,msg)forpinparams)_check_generic(self,params,len(self.__parameters__))subst=dict(zip(self.__parameters__,params))new_args=[]forarginself.__args__:ifisinstance(arg,TypeVar):arg=subst[arg]elifisinstance(arg,(_GenericAlias,GenericAlias)):subparams=arg.__parameters__ifsubparams:subargs=tuple(subst[x]forxinsubparams)arg=arg[subargs]new_args.append(arg)returnself.copy_with(tuple(new_args))defcopy_with(self,params):returnself.__class__(self.__origin__,params,name=self._name,inst=self._inst)def__repr__(self):ifself._name:name='typing.'+self._nameelse:name=_type_repr(self.__origin__)args=", ".join([_type_repr(a)forainself.__args__])returnf'{name}[{args}]'def__reduce__(self):ifself._name:origin=globals()[self._name]else:origin=self.__origin__args=tuple(self.__args__)iflen(args)==1andnotisinstance(args[0],tuple):args,=argsreturnoperator.getitem,(origin,args)def__mro_entries__(self,bases):ifself._name:# generic version of an ABC or built-in classreturnsuper().__mro_entries__(bases)ifself.__origin__isGeneric:ifProtocolinbases:return()i=bases.index(self)forbinbases[i+1:]:ifisinstance(b,_BaseGenericAlias)andbisnotself: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):ifnameisNone:name=origin.__name__super().__init__(origin,inst=inst,name=name)self._nparams=nparamsiforigin.__module__=='builtins':self.__doc__=f'A generic version of {origin.__qualname__}.'else:self.__doc__=f'A generic version of {origin.__module__}.{origin.__qualname__}.'@_tp_cachedef__getitem__(self,params):ifnotisinstance(params,tuple):params=(params,)msg="Parameters to generic types must be types."params=tuple(_type_check(p,msg)forpinparams)_check_generic(self,params,self._nparams)returnself.copy_with(params)defcopy_with(self,params):return_GenericAlias(self.__origin__,params,name=self._name,inst=self._inst)def__repr__(self):return'typing.'+self._namedef__subclasscheck__(self,cls):ifisinstance(cls,_SpecialGenericAlias):returnissubclass(cls.__origin__,self.__origin__)ifnotisinstance(cls,_GenericAlias):returnissubclass(cls,self.__origin__)returnsuper().__subclasscheck__(cls)def__reduce__(self):returnself._nameclass_CallableGenericAlias(_GenericAlias,_root=True):def__repr__(self):assertself._name=='Callable'iflen(self.__args__)==2andself.__args__[0]isEllipsis:returnsuper().__repr__()return(f'typing.Callable'f'[[{", ".join([_type_repr(a)forainself.__args__[:-1]])}], 'f'{_type_repr(self.__args__[-1])}]')def__reduce__(self):args=self.__args__ifnot(len(args)==2andargs[0]is...):args=list(args[:-1]),args[-1]returnoperator.getitem,(Callable,args)class_CallableType(_SpecialGenericAlias,_root=True):defcopy_with(self,params):return_CallableGenericAlias(self.__origin__,params,name=self._name,inst=self._inst)def__getitem__(self,params):ifnotisinstance(params,tuple)orlen(params)!=2:raiseTypeError("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.ifisinstance(args,list):params=(tuple(args),result)else:params=(args,result)returnself.__getitem_inner__(params)@_tp_cachedef__getitem_inner__(self,params):args,result=paramsmsg="Callable[args, result]: result must be a type."result=_type_check(result,msg)ifargsisEllipsis:returnself.copy_with((_TypingEllipsis,result))ifnotisinstance(args,tuple):args=(args,)args=tuple(_type_convert(arg)forarginargs)params=args+(result,)returnself.copy_with(params)class_TupleType(_SpecialGenericAlias,_root=True):@_tp_cachedef__getitem__(self,params):ifparams==():returnself.copy_with((_TypingEmpty,))ifnotisinstance(params,tuple):params=(params,)iflen(params)==2andparams[1]is...:msg="Tuple[t, ...]: t must be a type."p=_type_check(params[0],msg)returnself.copy_with((p,_TypingEllipsis))msg="Tuple[t0, t1, ...]: each t must be a type."params=tuple(_type_check(p,msg)forpinparams)returnself.copy_with(params)class_UnionGenericAlias(_GenericAlias,_root=True):defcopy_with(self,params):returnUnion[params]def__eq__(self,other):ifnotisinstance(other,_UnionGenericAlias):returnNotImplementedreturnset(self.__args__)==set(other.__args__)def__hash__(self):returnhash(frozenset(self.__args__))def__repr__(self):args=self.__args__iflen(args)==2:ifargs[0]istype(None):returnf'typing.Optional[{_type_repr(args[1])}]'elifargs[1]istype(None):returnf'typing.Optional[{_type_repr(args[0])}]'returnsuper().__repr__()def_value_and_type_iter(parameters):return((p,type(p))forpinparameters)class_LiteralGenericAlias(_GenericAlias,_root=True):def__eq__(self,other):ifnotisinstance(other,_LiteralGenericAlias):returnNotImplementedreturnset(_value_and_type_iter(self.__args__))==set(_value_and_type_iter(other.__args__))def__hash__(self):returnhash(frozenset(_value_and_type_iter(self.__args__)))classGeneric:"""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_cachedef__class_getitem__(cls,params):ifnotisinstance(params,tuple):params=(params,)ifnotparamsandclsisnotTuple:raiseTypeError(f"Parameter list to {cls.__qualname__}[...] cannot be empty")msg="Parameters to generic types must be types."params=tuple(_type_check(p,msg)forpinparams)ifclsin(Generic,Protocol):# Generic and Protocol can only be subscripted with unique type variables.ifnotall(isinstance(p,TypeVar)forpinparams):raiseTypeError(f"Parameters to {cls.__name__}[...] must all be type variables")iflen(set(params))!=len(params):raiseTypeError(f"Parameters to {cls.__name__}[...] must all be unique")else:# Subscripting a regular Generic subclass._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__'incls.__dict__:error=Genericincls.__orig_bases__else:error=Genericincls.__bases__andcls.__name__!='Protocol'iferror:raiseTypeError("Cannot inherit from plain Generic")if'__orig_bases__'incls.__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=Noneforbaseincls.__orig_bases__:if(isinstance(base,_GenericAlias)andbase.__origin__isGeneric):ifgvarsisnotNone:raiseTypeError("Cannot inherit from Generic[...] multiple types.")gvars=base.__parameters__ifgvarsisnotNone:tvarset=set(tvars)gvarset=set(gvars)ifnottvarset<=gvarset:s_vars=', '.join(str(t)fortintvarsiftnotingvarset)s_args=', '.join(str(g)forgingvars)raiseTypeError(f"Some type variables ({s_vars}) are"f" not listed in Generic[{s_args}]")tvars=gvarscls.__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()forbaseincls.__mro__[:-1]:# without objectifbase.__name__in('Protocol','Generic'):continueannotations=getattr(base,'__annotations__',{})forattrinlist(base.__dict__.keys())+list(annotations.keys()):ifnotattr.startswith('_abc_')andattrnotinEXCLUDED_ATTRIBUTES:attrs.add(attr)returnattrsdef_is_callable_members_only(cls):# PEP 544 prohibits using issubclass() with protocols that have non-method members.returnall(callable(getattr(cls,attr,None))forattrin_get_protocol_attrs(cls))def_no_init_or_replace_init(self,*args,**kwargs):cls=type(self)ifcls._is_protocol:raiseTypeError('Protocols cannot be instantiated')# Already using a custom `__init__`. No need to calculate correct# `__init__` to call. This can lead to RecursionError. See bpo-45121.ifcls.__init__isnot_no_init_or_replace_init:return# Initially, `__init__` of a protocol subclass is set to `_no_init_or_replace_init`.# The first instantiation of the subclass will call `_no_init_or_replace_init` which# searches for a proper new `__init__` in the MRO. The new `__init__`# replaces the subclass' old `__init__` (ie `_no_init_or_replace_init`). Subsequent# instantiation of the protocol subclass will thus use the new# `__init__` and no longer call `_no_init_or_replace_init`.forbaseincls.__mro__:init=base.__dict__.get('__init__',_no_init_or_replace_init)ifinitisnot_no_init_or_replace_init:cls.__init__=initbreakelse:# should not happencls.__init__=object.__init__cls.__init__(self,*args,**kwargs)def_allow_reckless_class_cheks():"""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:returnsys._getframe(3).f_globals['__name__']in['abc','functools']except(AttributeError,ValueError):# For platforms without _getframe().returnTrue_PROTO_WHITELIST={'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((notgetattr(cls,'_is_protocol',False)or_is_callable_members_only(cls))andissubclass(instance.__class__,cls)):returnTrueifcls._is_protocol:ifall(hasattr(instance,attr)and# All *methods* can be blocked by setting them to None.(notcallable(getattr(cls,attr,None))orgetattr(instance,attr)isnotNone)forattrin_get_protocol_attrs(cls)):returnTruereturnsuper().__instancecheck__(instance)classProtocol(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=Falsedef__init_subclass__(cls,*args,**kwargs):super().__init_subclass__(*args,**kwargs)# Determine if this is a protocol or a concrete subclass.ifnotcls.__dict__.get('_is_protocol',False):cls._is_protocol=any(bisProtocolforbincls.__bases__)# Set (or override) the protocol subclass hook.def_proto_hook(other):ifnotcls.__dict__.get('_is_protocol',False):returnNotImplemented# First, perform various sanity checks.ifnotgetattr(cls,'_is_runtime_protocol',False):if_allow_reckless_class_cheks():returnNotImplementedraiseTypeError("Instance and class checks can only be used with"" @runtime_checkable protocols")ifnot_is_callable_members_only(cls):if_allow_reckless_class_cheks():returnNotImplementedraiseTypeError("Protocols with non-method members"" don't support issubclass()")ifnotisinstance(other,type):# Same error message as for issubclass(1, int).raiseTypeError('issubclass() arg 1 must be a class')# Second, perform the actual structural compatibility check.forattrin_get_protocol_attrs(cls):forbaseinother.__mro__:# Check if the members appears in the class dictionary...ifattrinbase.__dict__:ifbase.__dict__[attr]isNone:returnNotImplementedbreak# ...or in annotations, if it is a sub-protocol.annotations=getattr(base,'__annotations__',{})if(isinstance(annotations,collections.abc.Mapping)andattrinannotationsandissubclass(other,Generic)andother._is_protocol):breakelse:returnNotImplementedreturnTrueif'__subclasshook__'notincls.__dict__:cls.__subclasshook__=_proto_hook# We have nothing more to do for non-protocols...ifnotcls._is_protocol:return# ... otherwise check consistency of bases, and prohibit instantiation.forbaseincls.__bases__:ifnot(basein(object,Generic)orbase.__module__in_PROTO_WHITELISTandbase.__name__in_PROTO_WHITELIST[base.__module__]orissubclass(base,Generic)andbase._is_protocol):raiseTypeError('Protocols can only inherit from other'' protocols, got %r'%base)cls.__init__=_no_init_or_replace_initclass_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):ifisinstance(origin,_AnnotatedAlias):metadata=origin.__metadata__+metadataorigin=origin.__origin__super().__init__(origin,origin)self.__metadata__=metadatadefcopy_with(self,params):assertlen(params)==1new_type=params[0]return_AnnotatedAlias(new_type,self.__metadata__)def__repr__(self):return"typing.Annotated[{}, {}]".format(_type_repr(self.__origin__),", ".join(repr(a)forainself.__metadata__))def__reduce__(self):returnoperator.getitem,(Annotated,(self.__origin__,)+self.__metadata__)def__eq__(self,other):ifnotisinstance(other,_AnnotatedAlias):returnNotImplementedreturn(self.__origin__==other.__origin__andself.__metadata__==other.__metadata__)def__hash__(self):returnhash((self.__origin__,self.__metadata__))classAnnotated:"""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):raiseTypeError("Type Annotated cannot be instantiated.")@_tp_cachedef__class_getitem__(cls,params):ifnotisinstance(params,tuple)orlen(params)<2:raiseTypeError("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,allow_special_forms=True)metadata=tuple(params[1:])return_AnnotatedAlias(origin,metadata)def__init_subclass__(cls,*args,**kwargs):raiseTypeError("Cannot subclass {}.Annotated".format(cls.__module__))defruntime_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! """ifnotissubclass(cls,Generic)ornotcls._is_protocol:raiseTypeError('@runtime_checkable can be only applied to protocol classes,'' got %r'%cls)cls._is_runtime_protocol=Truereturnclsdefcast(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). """returnvaldef_get_defaults(func):"""Internal helper to extract the default arguments, by name."""try:code=func.__code__exceptAttributeError:# Some built-in functions don't have __code__, __defaults__, etc.return{}pos_count=code.co_argcountarg_names=code.co_varnamesarg_names=arg_names[:pos_count]defaults=func.__defaults__or()kwdefaults=func.__kwdefaults__res=dict(kwdefaults)ifkwdefaultselse{}pos_offset=pos_count-len(defaults)forname,valueinzip(arg_names[pos_offset:],defaults):assertnamenotinresres[name]=valuereturnres_allowed_types=(types.FunctionType,types.BuiltinFunctionType,types.MethodType,types.ModuleType,WrapperDescriptorType,MethodWrapperType,MethodDescriptorType)defget_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. """ifgetattr(obj,'__no_type_check__',None):return{}# Classes require a special treatment.ifisinstance(obj,type):hints={}forbaseinreversed(obj.__mro__):ifglobalnsisNone:base_globals=sys.modules[base.__module__].__dict__else:base_globals=globalnsann=base.__dict__.get('__annotations__',{})forname,valueinann.items():ifvalueisNone:value=type(None)ifisinstance(value,str):value=ForwardRef(value,is_argument=False,is_class=True)value=_eval_type(value,base_globals,localns)hints[name]=valuereturnhintsifinclude_extraselse{k:_strip_annotations(t)fork,tinhints.items()}ifglobalnsisNone:ifisinstance(obj,types.ModuleType):globalns=obj.__dict__else:nsobj=obj# Find globalns for the unwrapped object.whilehasattr(nsobj,'__wrapped__'):nsobj=nsobj.__wrapped__globalns=getattr(nsobj,'__globals__',{})iflocalnsisNone:localns=globalnseliflocalnsisNone:localns=globalnshints=getattr(obj,'__annotations__',None)ifhintsisNone:# Return empty annotations for something that _could_ have them.ifisinstance(obj,_allowed_types):return{}else:raiseTypeError('{!r} is not a module, class, method, ''or function.'.format(obj))defaults=_get_defaults(obj)hints=dict(hints)forname,valueinhints.items():ifvalueisNone:value=type(None)ifisinstance(value,str):# class-level forward refs were handled above, this must be either# a module-level annotation or a function argument annotationvalue=ForwardRef(value,is_argument=notisinstance(obj,types.ModuleType),is_class=False,)value=_eval_type(value,globalns,localns)ifnameindefaultsanddefaults[name]isNone:value=Optional[value]hints[name]=valuereturnhintsifinclude_extraselse{k:_strip_annotations(t)fork,tinhints.items()}def_strip_annotations(t):"""Strips the annotations from a given type. """ifisinstance(t,_AnnotatedAlias):return_strip_annotations(t.__origin__)ifisinstance(t,_GenericAlias):stripped_args=tuple(_strip_annotations(a)foraint.__args__)ifstripped_args==t.__args__:returntreturnt.copy_with(stripped_args)ifisinstance(t,GenericAlias):stripped_args=tuple(_strip_annotations(a)foraint.__args__)ifstripped_args==t.__args__:returntreturnGenericAlias(t.__origin__,stripped_args)returntdefget_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 """ifisinstance(tp,_AnnotatedAlias):returnAnnotatedifisinstance(tp,(_BaseGenericAlias,GenericAlias)):returntp.__origin__iftpisGeneric:returnGenericreturnNonedefget_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) """ifisinstance(tp,_AnnotatedAlias):return(tp.__origin__,)+tp.__metadata__ifisinstance(tp,(_GenericAlias,GenericAlias)):res=tp.__args__iftp.__origin__iscollections.abc.Callableandres[0]isnotEllipsis:res=(list(res[:-1]),res[-1])returnresreturn()defno_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. """ifisinstance(arg,type):arg_attrs=arg.__dict__.copy()forattr,valinarg.__dict__.items():ifvalinarg.__bases__+(arg,):arg_attrs.pop(attr)forobjinarg_attrs.values():ifisinstance(obj,types.FunctionType):obj.__no_type_check__=Trueifisinstance(obj,type):no_type_check(obj)try:arg.__no_type_check__=TrueexceptTypeError:# built-in classespassreturnargdefno_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)defwrapped_decorator(*args,**kwds):func=decorator(*args,**kwds)func=no_type_check(func)returnfuncreturnwrapped_decoratordef_overload_dummy(*args,**kwds):"""Helper for @overload to raise when called."""raiseNotImplementedError("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.")defoverload(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_dummydeffinal(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. """returnf# 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=_SpecialGenericAliasHashable=_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_checkableclassSupportsInt(Protocol):"""An ABC with one abstract method __int__."""__slots__=()@abstractmethoddef__int__(self)->int:pass@runtime_checkableclassSupportsFloat(Protocol):"""An ABC with one abstract method __float__."""__slots__=()@abstractmethoddef__float__(self)->float:pass@runtime_checkableclassSupportsComplex(Protocol):"""An ABC with one abstract method __complex__."""__slots__=()@abstractmethoddef__complex__(self)->complex:pass@runtime_checkableclassSupportsBytes(Protocol):"""An ABC with one abstract method __bytes__."""__slots__=()@abstractmethoddef__bytes__(self)->bytes:pass@runtime_checkableclassSupportsIndex(Protocol):"""An ABC with one abstract method __index__."""__slots__=()@abstractmethoddef__index__(self)->int:pass@runtime_checkableclassSupportsAbs(Protocol[T_co]):"""An ABC with one abstract method __abs__ that is covariant in its return type."""__slots__=()@abstractmethoddef__abs__(self)->T_co:pass@runtime_checkableclassSupportsRound(Protocol[T_co]):"""An ABC with one abstract method __round__ that is covariant in its return type."""__slots__=()@abstractmethoddef__round__(self,ndigits:int=0)->T_co:passdef_make_nmtuple(name,types,module,defaults=()):fields=[nforn,tintypes]types={n:_type_check(t,f"field {n} annotation must be a type")forn,tintypes}nm_tpl=collections.namedtuple(name,fields,defaults=defaults,module=module)nm_tpl.__annotations__=nm_tpl.__new__.__annotations__=typesreturnnm_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__'})classNamedTupleMeta(type):def__new__(cls,typename,bases,ns):assertbases[0]is_NamedTupletypes=ns.get('__annotations__',{})default_names=[]forfield_nameintypes:iffield_nameinns:default_names.append(field_name)elifdefault_names:raiseTypeError(f"Non-default namedtuple field {field_name} "f"cannot follow default field"f"{'s'iflen(default_names)>1else''} "f"{', '.join(default_names)}")nm_tpl=_make_nmtuple(typename,types.items(),defaults=[ns[n]fornindefault_names],module=ns['__module__'])# update from user namespace without overriding special namedtuple attributesforkeyinns:ifkeyin_prohibited:raiseAttributeError("Cannot overwrite NamedTuple attribute "+key)elifkeynotin_specialandkeynotinnm_tpl._fields:setattr(nm_tpl,key,ns[key])returnnm_tpldefNamedTuple(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)]) """iffieldsisNone:fields=kwargs.items()elifkwargs:raiseTypeError("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=Nonereturn_make_nmtuple(typename,fields,module=module)_NamedTuple=type.__new__(NamedTupleMeta,'NamedTuple',(),{})def_namedtuple_mro_entries(bases):iflen(bases)>1:raiseTypeError("Multiple inheritance with NamedTuple is not supported")assertbases[0]isNamedTuplereturn(_NamedTuple,)NamedTuple.__mro_entries__=_namedtuple_mro_entriesclass_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. """forbaseinbases:iftype(base)isnot_TypedDictMeta:raiseTypeError('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,module=tp_dict.__module__)forn,tpinown_annotations.items()}required_keys=set()optional_keys=set()forbaseinbases: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)iftotal:required_keys.update(own_annotation_keys)else:optional_keys.update(own_annotation_keys)tp_dict.__annotations__=annotationstp_dict.__required_keys__=frozenset(required_keys)tp_dict.__optional_keys__=frozenset(optional_keys)ifnothasattr(tp_dict,'__total__'):tp_dict.__total__=totalreturntp_dict__call__=dict# static methoddef__subclasscheck__(cls,other):# Typed dicts are only for static structural subtyping.raiseTypeError('TypedDict does not support instance and class checks')__instancecheck__=__subclasscheck__defTypedDict(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+ """iffieldsisNone:fields=kwargselifkwargs:raiseTypeError("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):passreturn_TypedDictMeta(typename,(),ns,total=total)_TypedDict=type.__new__(_TypedDictMeta,'TypedDict',(),{})TypedDict.__mro_entries__=lambdabases:(_TypedDict,)defNewType(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 """defnew_type(x):returnxnew_type.__name__=namenew_type.__supertype__=tpreturnnew_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=FalseclassIO(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@abstractmethoddefmode(self)->str:pass@property@abstractmethoddefname(self)->str:pass@abstractmethoddefclose(self)->None:pass@property@abstractmethoddefclosed(self)->bool:pass@abstractmethoddeffileno(self)->int:pass@abstractmethoddefflush(self)->None:pass@abstractmethoddefisatty(self)->bool:pass@abstractmethoddefread(self,n:int=-1)->AnyStr:pass@abstractmethoddefreadable(self)->bool:pass@abstractmethoddefreadline(self,limit:int=-1)->AnyStr:pass@abstractmethoddefreadlines(self,hint:int=-1)->List[AnyStr]:pass@abstractmethoddefseek(self,offset:int,whence:int=0)->int:pass@abstractmethoddefseekable(self)->bool:pass@abstractmethoddeftell(self)->int:pass@abstractmethoddeftruncate(self,size:int=None)->int:pass@abstractmethoddefwritable(self)->bool:pass@abstractmethoddefwrite(self,s:AnyStr)->int:pass@abstractmethoddefwritelines(self,lines:List[AnyStr])->None:pass@abstractmethoddef__enter__(self)->'IO[AnyStr]':pass@abstractmethoddef__exit__(self,type,value,traceback)->None:passclassBinaryIO(IO[bytes]):"""Typed version of the return of open() in binary mode."""__slots__=()@abstractmethoddefwrite(self,s:Union[bytes,bytearray])->int:pass@abstractmethoddef__enter__(self)->'BinaryIO':passclassTextIO(IO[str]):"""Typed version of the return of open() in text mode."""__slots__=()@property@abstractmethoddefbuffer(self)->BinaryIO:pass@property@abstractmethoddefencoding(self)->str:pass@property@abstractmethoddeferrors(self)->Optional[str]:pass@property@abstractmethoddefline_buffering(self)->bool:pass@property@abstractmethoddefnewlines(self)->Any:pass@abstractmethoddef__enter__(self)->'TextIO':passclassio:"""Wrapper namespace for IO generic classes."""__all__=['IO','TextIO','BinaryIO']IO=IOTextIO=TextIOBinaryIO=BinaryIOio.__name__=__name__+'.io'sys.modules[io.__name__]=ioPattern=_alias(stdlib_re.Pattern,1)Match=_alias(stdlib_re.Match,1)classre:"""Wrapper namespace for re type aliases."""__all__=['Pattern','Match']Pattern=PatternMatch=Matchre.__name__=__name__+'.re'sys.modules[re.__name__]=re
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