Python logging example

log.py

# Credits: https://gist.github.com/nguyenkims
import logging
import sys
from logging.handlers import TimedRotatingFileHandler

FORMATTER = logging.Formatter("[%(asctime)s][%(name)s][%(levelname)s] - %(message)s")
LOG_FILE = "app.log"


def make_console_handler():
    console_handler = logging.StreamHandler(sys.stdout)
    console_handler.setFormatter(FORMATTER)
    return console_handler


def make_file_handler():
    file_handler = TimedRotatingFileHandler(LOG_FILE, when='midnight')
    file_handler.setFormatter(FORMATTER)
    return file_handler


def get_logger(name):
    logger = logging.getLogger(name)

    logger.addHandler(make_console_handler())
    fh = make_file_handler()
    fh.setLevel(logging.DEBUG)
    logger.addHandler(fh)

    # with this pattern, it's rarely necessary to propagate the error up to parent
    logger.propagate = False

    return logger


def main():
    log = get_logger(__name__)
    log.debug('Quirky bug')
    log.info('Important info')
    log.warning('Ultimatom')

    try:
        x = 1 / 0
    except ZeroDivisionError as err:
        log.error(err, exc_info=1)


if __name__ == '__main__':
    import argparse
    import logging

    parser = argparse.ArgumentParser()
    parser.add_argument("-v", "--verbose", help="increase output verbosity",
                        action="store_true")

    args = parser.parse_args()
    if args.verbose:
        logging.basicConfig(level=logging.DEBUG)

    main()
    exit()