shell_utils.py 文件源码

def get_argparse_extension_checker(choices, dir_allowed=False):
    """Get an :class:`argparge.Action` class that can check for correct extensions.

    Returns:
        argparse.Action: a class (not an instance) of an argparse action.
    """

    class Act(argparse.Action):
        def __call__(self, parser, namespace, fname, option_string=None):
            is_valid = any(map(lambda choice: fname[-len(choice):] == choice, choices))

            if not is_valid and dir_allowed and os.path.isdir(fname):
                is_valid = True

            if is_valid:
                setattr(namespace, self.dest, fname)
            else:
                option_string = '({})'.format(option_string) if option_string else ''
                parser.error("File doesn't end with one of {}{}".format(choices, option_string))

    return Act