python argparse - either both optional arguments or else neither one

Question

I have a program that uses a default name and password. I\'m using argparse to allow the user to specify command line options, and I would like to enable the user to provid

Answer 1

I know this is more than two years late, but I found a nice and concise way to do it:

if bool(ns.username) ^ bool(ns.password):
    parser.error('--username and --password must be given together')

^ is the XOR operator in Python. To require both arguments given at the command line is essentially an XOR test.