main.py 文件源码

def docopt_wrapper(usage, real_usage, **keywords):
    """ A wrapper around the real docopt parser.
    Redirects a failed command to /dev/null and prints the proper
    real_usage message, instead of just the usage string from usage.

    :param usage: The simplified usage string to parse
    :type usage: str
    :param real_usage: The original usage string to parse
    :type real_usage: str
    :param keywords: The keyword arguments to pass to docopt
    :type keywords: dict
    :returns: The parsed arguments
    :rtype: dict
    """

    base_subcommand = keywords.pop('base_subcommand')
    subcommand = keywords.pop('subcommand')

    try:
        stdout = sys.stdout

        # We run docopt twice (once with the real usage string and
        # once with the modified usage string) in order to populate
        # the 'real' arguments properly.
        with open(os.devnull, 'w') as nullfile:
            sys.stdout = nullfile
            real_arguments = docopt.docopt(
                real_usage,
                argv=[base_subcommand])
            arguments = docopt.docopt(
                usage,
                **keywords)
            sys.stdout = stdout

        real_arguments.update(arguments)
        real_arguments[subcommand] = True
        return real_arguments

    except docopt.DocoptExit:
        sys.stdout = stdout
        print(real_usage.strip(), file=sys.stderr)
        sys.exit(1)

    except SystemExit:
        sys.stdout = stdout

        if "argv" in keywords and any(h in ("-h", "--help")
                                      for h in keywords["argv"]):
            print(real_usage.strip())
        elif "version" in keywords and any(v in ("--version")
                                           for v in keywords["argv"]):
            print(keywords["version"].strip())

        sys.exit()