python - Argparse: Required argument 'y' if 'x' is present -

i have requirement follows:

./xyifier --prox --lport lport --rport rport 

for argument prox , use action='store_true' check if present or not. not require of arguments. but, if --prox set require rport , lport well. there easy way of doing argparse without writing custom conditional coding.

more code:

non_int.add_argument('--prox', action='store_true', help='flag turn on proxy') non_int.add_argument('--lport', type=int, help='listen port.') non_int.add_argument('--rport', type=int, help='proxy port.') 

no, there isn't option in argparse make mutually inclusive sets of options.

the simplest way deal be:

if args.prox , args.lport none , args.rport none:     parser.error("--prox requires --lport , --rport.")