In "Python 3.7 Documentation > Python HOWTOs > Argparse Tutorial" (https://docs.python.org/3.7/howto/argparse.html), search this page for

elif args.verbosity >= 1:

The operator ">=" should read "==" because args.verbosity cannot be 2 or greater after the if statement.

You would find the original codes unreasonable until you go through "if args.verbosity >= 1:".