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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _parse_args(argv):
 """ Show supported config format types or usage. :param argv: Argument list to parse or None (sys.argv will be set). :return: argparse.Namespace object or None (exit before return) """

    parser = make_parser()
    args = parser.parse_args(argv)
    LOGGER.setLevel(to_log_level(args.loglevel))

    if args.inputs:
        if '-' in args.inputs:
            args.inputs = sys.stdin
    else:
        if args.list:
            _show_psrs()
        elif args.env:
            cnf = os.environ.copy()
            _output_result(cnf, args.output, args.otype or "json", None, None)
            sys.exit(0)
        else:
            parser.print_usage()
            sys.exit(1)

    if args.validate and args.schema is None:
        _exit_with_output("--validate option requires --scheme option", 1)

    return args