def merge_arg(cmd_arg, ini_arg):
    """
    Merge command line argument and configure file argument.
        The cmd_args has higher priority than ini_arg.
        Only none-empty argument will be considered.
    """
    if isinstance(cmd_arg, (list, tuple)):
        cmd = cmd_arg[0]
        return cmd if cmd else ini_arg
    else:
        return cmd_arg if cmd_arg else ini_arg