Example of using Python logging

log_example

#! /usr/bin/env python

import logging
import argparse

parser = argparse.ArgumentParser()

group = parser.add_mutually_exclusive_group()
group.add_argument('-v', '--verbose', dest='verbose', action='count', help='Enable debugging - multiple uses prints more messages')
group.add_argument('--loglevel', dest='loglevel', action='store', help='Set log level: DEBUG, INFO, WARNING, ERROR, CRITICAL')

args = parser.parse_args()

logging.basicConfig(format='%(asctime)s %(levelname)s %(pathname)s:%(lineno)d %(msg)s')
log = logging.getLogger()
log.setLevel(args.loglevel or (logging.WARNING - (args.verbose or 0) * 10))

log.debug('This is a debugging message')
log.info('This is an informational message')
log.warn('This is a warning message')
log.error('This is an error message')
log.fatal('This is a fatal/critical message')