Method param_spec

mypy/types.py:2423–2440

Return ParamSpec if callable can be called with one. A Callable accepting ParamSpec P args (*args, **kwargs) must have the two final parameters like this: *args: P.args, **kwargs: P.kwargs.

(self)

        return a

    def param_spec(self) -> ParamSpecType | None:
        """Return ParamSpec if callable can be called with one.

        A Callable accepting ParamSpec P args (*args, **kwargs) must have the
        two final parameters like this: *args: P.args, **kwargs: P.kwargs.
        """
        if len(self.arg_types) < 2:
            return None
        if self.arg_kinds[-2] != ARG_STAR or self.arg_kinds[-1] != ARG_STAR2:
            return None
        arg_type = self.arg_types[-2]
        if not isinstance(arg_type, ParamSpecType):
            return None

        # Prepend prefix for def f(prefix..., *args: P.args, **kwargs: P.kwargs) -> ...
        # TODO: confirm that all arg kinds are positional
        prefix = Parameters(self.arg_types[:-2], self.arg_kinds[:-2], self.arg_names[:-2])
        return arg_type.copy_modified(flavor=ParamSpecFlavor.BARE, prefix=prefix)

    def normalize_trivial_unpack(self) -> None:
        # Normalize trivial unpack in var args as *args: *tuple[X, ...] -> *args: X in place.