Simplest form of logging in Python.

logging_in_python.py

import logging

# logging levels
# https://docs.python.org/3.6/library/logging.html#logging-levels

# https://docs.python.org/3.6/library/logging.html#logrecord-attributes
logging.basicConfig(filename='logger.log',
    filemode='w',
    format='%(lineno)d %(levelname)s: %(asctime)s %(funcName)s %(message)s %(thread)d',
    level=logging.WARNING) 
logging.debug('This message should go to the log file')
logging.info('I told ya!')
logging.warning('Watch out!')
logging.error('An error occured. Program has halt.')