When using Python's argparse module you can use parse_known_args() to parse only arguments that are known to the parser and any additional arguments are returned separately.
However, this fact is not denoted in the usage/help string. Of course I could put it in the description field of the parser, but I wonder if there's a nice way to include it in the usage line.
What I'm looking for is an output of e.g. usage: test [-h] ... instead of usage: test [-h]