manipulating log level with python argparse

verbos-argpary-example.py

import argparse
import logging

parser = argparse.ArgumentParser()
parser.add_argument('--verbose', '-v', action='count', default=1)
args = parser.parse_args()

args.verbose = 70 - (10*args.verbose) if args.verbose > 0 else 0

logging.basicConfig(level=args.verbose, format='%(asctime)s %(levelname)s: %(message)s',
                    datefmt='%Y-%m-%d %H:%M:%S')

logging.debug('im a DEBUG message')
logging.info('im a INFO message')
logging.warning('im a WARNING message')
logging.critical('im a CRITICAL message')
logging.error('im a ERROR message')

purpose

example to show how to manipulate log levels with python argparse. basically add more 'v' to the start parameters will increase the log level to higher verbosity. This example defaults log nothing (be silent) without any parameters given.

examples:

• default is to log nothing (be silent)

 $verbos-argpary-example.py
 $

• will log CRITICAL level

 $verbos-argpary-example.py -v
 2015-02-04 11:00:46 CRITICAL: im a CRITICAL message

• will log everything up to WARNING level

 $verbos-argpary-example.py -vvv 
 2015-02-04 10:59:22 WARNING: im a WARNING message
 2015-02-04 10:59:22 CRITICAL: im a CRITICAL message
 2015-02-04 10:59:22 ERROR: im a ERROR message

• at some point adding more -v does not have an impact anymore

 $verbos-argpary-example.py -vvvvvvvvvv
 2015-02-04 11:09:18 DEBUG: im a DEBUG message
 2015-02-04 11:09:18 INFO: im a INFO message
 2015-02-04 11:09:18 WARNING: im a WARNING message
 2015-02-04 11:09:18 CRITICAL: im a CRITICAL message
 2015-02-04 11:09:18 ERROR: im a ERROR message

Thanks for posting this!! I used a level of 40 instead, so that logging.info() messages trigger from the first -v
args.verbose = 40 - (10*args.verbose) if args.verbose > 0 else 0
Best :)

This is so great. Thank you.

I also recommend setting the initial value to 40.