According to the docs it should be

>>> xgrp = parser.add_argument_group()

rather than

>>> xgrp = grp.add_argument_group()


This seems to work:



>>> parser = argparse.ArgumentParser()
>>> grp = parser.add_argument_group('Database settings')
>>> grp.add_argument('--db-config')
_StoreAction(option_strings=['--db-config'], dest='db_config', nargs=None, const=None, default=None, type=None, choices=None, help=None, metavar=None)
>>> xgrp = parser.add_argument_group()
>>> xgrp.add_argument('--db-password')
_StoreAction(option_strings=['--db-password'], dest='db_password', nargs=None, const=None, default=None, type=None, choices=None, help=None, metavar=None)
>>> parser.parse_args(['-h'])
usage: [-h] [--db-config DB_CONFIG] [--db-password DB_PASSWORD]

options:
  -h, --help            show this help message and exit

Database settings:
  --db-config DB_CONFIG

  --db-password DB_PASSWORD