argparse: nargs with multiple flags in one dash?

问题

If I try running python test.py -bf with the below code, I get bar=f and foo=foo1 instead of the desired result (bar=bar1 and foo=foo1). How would I achieve the desired result?

import argparse

ap = argparse.ArgumentParser(description='test')
ap.add_argument('--bar', '-b', nargs='?', const='bar1')
ap.add_argument('--foo', '-f', nargs='?', const='foo1')
args = ap.parse_args()

来源：https://stackoverflow.com/questions/62747802/argparse-nargs-with-multiple-flags-in-one-dash