bpo-43783: Add ParamSpecArgs/Kwargs (GH-25298)
diff --git a/Lib/typing.py b/Lib/typing.py
index 6224930..6461ba2 100644
--- a/Lib/typing.py
+++ b/Lib/typing.py
@@ -114,6 +114,8 @@
'no_type_check_decorator',
'NoReturn',
'overload',
+ 'ParamSpecArgs',
+ 'ParamSpecKwargs',
'runtime_checkable',
'Text',
'TYPE_CHECKING',
@@ -727,6 +729,44 @@ def __init__(self, name, *constraints, bound=None,
self.__module__ = def_mod
+class ParamSpecArgs(_Final, _Immutable, _root=True):
+ """The args for a ParamSpec object.
+
+ Given a ParamSpec object P, P.args is an instance of ParamSpecArgs.
+
+ ParamSpecArgs objects have a reference back to their ParamSpec:
+
+ P.args.__origin__ is P
+
+ This type is meant for runtime introspection and has no special meaning to
+ static type checkers.
+ """
+ def __init__(self, origin):
+ self.__origin__ = origin
+
+ def __repr__(self):
+ return f"{self.__origin__.__name__}.args"
+
+
+class ParamSpecKwargs(_Final, _Immutable, _root=True):
+ """The kwargs for a ParamSpec object.
+
+ Given a ParamSpec object P, P.kwargs is an instance of ParamSpecKwargs.
+
+ ParamSpecKwargs objects have a reference back to their ParamSpec:
+
+ P.kwargs.__origin__ is P
+
+ This type is meant for runtime introspection and has no special meaning to
+ static type checkers.
+ """
+ def __init__(self, origin):
+ self.__origin__ = origin
+
+ def __repr__(self):
+ return f"{self.__origin__.__name__}.kwargs"
+
+
class ParamSpec(_Final, _Immutable, _TypeVarLike, _root=True):
"""Parameter specification variable.
@@ -776,8 +816,13 @@ def add_two(x: float, y: float) -> float:
__slots__ = ('__name__', '__bound__', '__covariant__', '__contravariant__',
'__dict__')
- args = object()
- kwargs = object()
+ @property
+ def args(self):
+ return ParamSpecArgs(self)
+
+ @property
+ def kwargs(self):
+ return ParamSpecKwargs(self)
def __init__(self, name, *, bound=None, covariant=False, contravariant=False):
self.__name__ = name
@@ -1662,10 +1707,12 @@ def get_origin(tp):
get_origin(Generic[T]) is Generic
get_origin(Union[T, int]) is Union
get_origin(List[Tuple[T, T]][int]) == list
+ get_origin(P.args) is P
"""
if isinstance(tp, _AnnotatedAlias):
return Annotated
- if isinstance(tp, (_BaseGenericAlias, GenericAlias)):
+ if isinstance(tp, (_BaseGenericAlias, GenericAlias,
+ ParamSpecArgs, ParamSpecKwargs)):
return tp.__origin__
if tp is Generic:
return Generic