def run_command_from_args(args):
    """Run a subcommand with previously parsed arguments in an argparse namespace.

    This function is intended to be used for unit testing.

    Parameters
    ----------
    args : Namespace
        Command line arguments are stored as attributes of a Namespace.
        The args are obtained by calling parse_argument_list().

    Returns
    -------
    Returns 0 on success if it completes with no exceptions.
    """
    return args.func(args)
