parent1.add_argument('--config')
parent2 = argparse.ArgumentParser(add_help=False)
parent2.add_argument('--config')
parser = argparse.ArgumentParser(parents=[parent1, parent2],
    conflict_handler='resolve')

def foo(parser):
    print([(id(a), a.dest, a.option_strings) for a in parser._actions])
foo(parent1)
foo(parent2)
foo(parser)
argparse conflict resolver for options in subcommands turns keyword argument into positional argument