types.py 文件源码

def _metaclass_check_getitem_type_decl(cls, type_decl):
        # Callable[[T, ...], T]
        if not check_getitem_tuple(type_decl, 2):
            return False

        # return type.
        if nontype_object(type_decl[1]):
            return False

        # types of parameters.
        if isinstance(type_decl[0], abc.Iterable):
            # [T, ...]
            for T in type_decl[0]:
                if nontype_object(T):
                    return False
            else:
                return True
        else:
            # special case, Ellipsis.
            return type_decl[0] is Ellipsis