parser = argparse.ArgumentParser(description='some description', epilog=
    'At least one of -n, -o, --name, or --othername is required and they all do the same thing.'
    )
parser.add_argument('-d', '--dummy', dest='dummy', default=None, help=
    'some other flag')
stuff = parser.add_mutually_exclusive_group(required=True)
stuff.add_argument('-n', dest='name', action='store', choices=all_grids,
    help=argparse.SUPPRESS)
stuff.add_argument('-o', dest='name', action='store', choices=all_grids,
    help=argparse.SUPPRESS)
stuff.add_argument('--name', dest='name', action='store', choices=all_grids,
    help=argparse.SUPPRESS)
stuff.add_argument('--othername', dest='name', action='store', choices=
    all_grids, help='')
args = parser.parse_args()
How can I get Python Argparse to list choices only once?