Python command line settable logging verbosity example.

command_line_logging_arguments.py

#!/usr/bin/env python2.7

import argparse
import logging

def type_loglevel(level):
    try:
        result = getattr(logging, level.upper())
    except AttributeError:
        raise argparse.ArgumentTypeError("'%s' is not a valid log level. Please use %s" % \
                                         (level, [x for x in logging._levelNames.keys() if isinstance(x, str)]))
    return result

parser = argparse.ArgumentParser(description='My description goes here')
parser.add_argument('-l', '--loglevel', type=type_loglevel, default='INFO',
                   help='Log level verbosity (default: INFO)')
args = parser.parse_args()
logging.basicConfig(level=args.loglevel)

logging.debug('This is a test debug message')