argparse parse_known_args()

argparse_test.py

import argparse

parser = argparse.ArgumentParser(add_help=False)
parser.add_argument('--env', '-e', action='append')
parser.add_argument('--hostname', '-h')

known, unknown = parser.parse_known_args(['-e', 'key=value'])
print '1. known', known
print '1. unknown', unknown
assert known.env == ['key=value']

known, unknown = parser.parse_known_args(['-te', 'key=value'])
print '2. known', known
print '2. unknown', unknown
assert known.env == ['key=value']