Using python argparse, I'd like to support the following syntax:
asm2k.py -o XXXXX bbl.asm

Specifically, the -o option can take 1 or more letters, where the letters are from the set of "ARLQTNZCFXPB".

My attempt with just ABC for brevity:

parser.add_argument('-o', '--options', nargs='+', choices=('A','B','C'), help='Control Options')

But this doesn't allow combinations like '-o AC' or '-o BCA'. Is this use case supported?