def main():
    paser = argparse.ArgumentParser(
        description="rmlastfile.py"
    )
    paser.add_argument("--subdir", required=False, help="locate to logdir")
    paser.add_argument("--parentdir", required=False, help="locate to the parentdir of logdir\"s ")
    args = paser.parse_args()

usage: rmlastfile.py [- h] [--subdir SUBDIR] [--parentdir PARENTDIR]

rmlastfile.py

optional arguments:
-h,-- help show this help message and exit
-- subdir SUBDIR locate to logdir
-- parentdir PARENTDIR locate to the parentdir of logdir"s

how do I implement these two parameters-- subdir-- parentdir at least one of which is a required required?