An example logger for Python3

pylogging.py

#!/usr/bin/env python3

# Adapted from https://docs.python.org/2/howto/logging-cookbook.html

'''
pylogging.py - Template to add logging to something in Python3

Logging level accepts strings or a numeral value:
CRITICAL      50
ERROR         40
WARNING       30
INFO          20
DEBUG         10
NOTSET        0 (Default, logs at warning for some reason)
'''

import logging

# You likely want to change this to an 'spam.eggs.foo' string for smaller projects.
# This value sets the minimum for the program, so if this is set to INFO for example and others
# attempt to use a lower level like DEBUG, it will still only log INFO or higher.
logger = logging.getLogger(__name__)
logger.setLevel(logging.DEBUG)

# create file handler that logs at debug to file 'file.log'
fh = logging.FileHandler('file.log')
fh.setLevel(logging.DEBUG)

# create console handler for iostream.  It is common to set this to WARNING.
ch = logging.StreamHandler()
ch.setLevel(logging.WARNING)

# create formatter and add it to the handlers
# Uses time.strftime(format[, t]), see
# https://docs.python.org/3/library/time.html#time.strftime
formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')
fh.setFormatter(formatter)
ch.setFormatter(formatter)

# add the handlers to the logger
logger.addHandler(fh)
logger.addHandler(ch)

#logging examples.
logger.critical("logger message critical")
logger.error("logger message error")
logger.warning("logger message warning, this is also sometimes called notice")
logger.info("logger message info")
logger.debug("logger message debug")