如何检查特定的子解析器?
import argparse
if __name__ == "__main__":
mainparser = argparse.ArgumentParser()
submainadder = mainparser.add_subparsers(title='subcommands')
parser_ut = submainadder.add_parser('unittest')
stuff = mainparser.parse_args()
# if 'unittest' was selected:
# do_things()