cli.py 文件源码

def nonnegative_int(value):
    """Converts value to an int and checks that it is not negative.

    This function should used as the type parameter for argparse
    arguments.

    :param str value: value provided on the command line

    :returns: integer representation of value
    :rtype: int

    :raises argparse.ArgumentTypeError: if value isn't a non-negative integer

    """
    try:
        int_value = int(value)
    except ValueError:
        raise argparse.ArgumentTypeError("value must be an integer")

    if int_value < 0:
        raise argparse.ArgumentTypeError("value must be non-negative")
    return int_value