argparse '--' not working?

[Neal Becker]

It is a 'standard' behaviour that a lone '--' terminates options.  argparse 
says:

If you have positional arguments that must begin with '-' and don’t look 
like negative numbers, you can insert the pseudo-argument '--' which tells 
parse_args that everything after that is a positional argument:

But it doesn't seem to work:

import argparse
    
parser = argparse.ArgumentParser()
parser.add_argument ('--submit', '-s', action='store_true')
parser.add_argument ('--list', '-l', action='store_true')
opt = parser.parse_args()

./queue --submit -- test1.py -n
usage: queue [-h] [--submit] [--list]
queue: error: unrecognized arguments: -- test1.py -n