python positional arguments argparse code example
Example 1: argparse list of options
parser.add_argument('--list',
default='all',
const='all',
nargs='?',
choices=['servers', 'storage', 'all'],
help='list servers, storage, or both (default: %(default)s)')
Example 2: python argparser flags
parser.add_argument("-v", "--verbose", action="store_true",
help="verbose output")