import logging
import argparse

...

parser.add_argument('-v', '--verbose', action="count", help="Set verbose lever by specifying multiple -v values.")

...

logger = logging.StreamHandler()

if not args.verbose:
   logger.setLevel('ERROR')
elif args.verbose == 1:
   logger.setLevel('WARNING')
elif args.verbose == 2:
   logger.setLevel('INFO')
else:
   logger.setLevel('DEBUG')