Python Logging #python

README.md

Python Logging

bin-script

#!/usr/bin/env python3

import sys
import argparse
import logging
import custom_module

def verbose_to_loglevel(c):
    loglevel = logging.WARNING
    if c == 1:
        loglevel = logging.INFO
    elif c >= 2:
        loglevel = logging.DEBUG
    return loglevel

def main(args):
    args_parser = argparse.ArgumentParser()
    args_parser.add_argument(
        '-v',
        '--verbose',
        help='Log Verbose Messages',
        action='count',
        default=0)
    args = args_parser.parse_args(args)
    logging.basicConfig(level=verbose_to_loglevel(args.verbose))
    # in a script or executable module, the __name__ becomes __main__
    logger = logging.getLogger(__name__)
    logger.info('Done!')

if __name__ == '__main__':
    main(sys.argv[1:])

custom_module.py

import logging

# by convention the logger name corresponds to the module name
# which we can utilise by just using __name__
logger = logging.getLogger(__name__)

def f1():
    logger.info('calling f1')
    return


def f2():
    # we don't always have to use the module name
    # especially if we think that f2 represents its own unique entity
    # do note there's also %(funcName)s that is available in the format
    # however that's global
    logger.getLogger(__name__ + '.f2')
    return