logging.md

Logging

Pyhton standard library comes with a powerful logging module.

Usage

By default, there are 5 standard levels indicating the severity of events: DEBUG, INFO, WARNING, ERROR and CRITICAL. The default logger configurarion will log all events with level WARNING or above. Example:

import logging

logging.debug('This is a debug message')
logging.info('This is an info message')
logging.warning('This is a warning message')
logging.error('This is an error message')
logging.critical('This is a critical message')

# Outputs:
# WARNING:root:This is a warning message
# ERROR:root:This is an error message
# CRITICAL:root:This is a critical message

Configurating the logger

import logging

logging.basicConfig(filename='log.txt', filemode='w', level=logging.DEBUG, format='%(name)s - %(levelname)s - %(message)s')
logging.warning('This will log every log level to a file.')

Adding time info:

import logging

logging.basicConfig(format='%(asctime)s - %(message)s', datefmt='%d-%b-%y %H:%M:%S')
logging.warning('Admin logged out')

References:

• Logging in Python
• Logging Cookbook