type_util.py 文件源码

def get_Generic_parameters(tp, generic_supertype):
    """tp must be a subclass of generic_supertype.
    Retrieves the type values from tp that correspond to parameters
    defined by generic_supertype.

    E.g. get_Generic_parameters(tp, typing.Mapping) is equivalent
    to get_Mapping_key_value(tp) except for the error message.

    Note that get_Generic_itemtype(tp) is not exactly equal to
    get_Generic_parameters(tp, typing.Container), as that method
    additionally contains treatment for typing.Tuple and typing.Iterable.
    """
    try:
        res = _select_Generic_superclass_parameters(tp, generic_supertype)
    except TypeError:
        res = None
    if res is None:
        raise TypeError("%s has no proper parameters defined by %s."%
                (type_str(tp), type_str(generic_supertype)))
    else:
        return tuple(res)