import logging import sys LEVELS = {'debug': logging.DEBUG,           'info': logging.INFO,           'warning': logging.WARNING,           'error': logging.ERROR,           'critical': logging.CRITICAL} if len(sys.argv) > 1:     level_name = sys.argv[1]     level = LEVELS.get(level_name, logging.NOTSET)     logging.basicConfig(level=level) 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 error message')

$ python logging_level_example.py debug DEBUG:root:This is a debug message INFO:root:This is an info message WARNING:root:This is a warning message ERROR:root:This is an error message CRITICAL:root:This is a critical error message $ python logging_level_example.py info INFO:root:This is an info message WARNING:root:This is a warning message ERROR:root:This is an error message CRITICAL:root:This is a critical error message

import logging # create logger logger = logging.getLogger("simple_example") logger.setLevel(logging.DEBUG) # create console handler and set level to debug ch = logging.StreamHandler() ch.setLevel(logging.DEBUG) # create formatter formatter = logging.Formatter("%(asctime)s - %(name)s - %(levelname)s - %(message)s") # add formatter to ch ch.setFormatter(formatter) # add ch to logger logger.addHandler(ch) # "application" code logger.debug("debug message") logger.info("info message") logger.warn("warn message") logger.error("error message") logger.critical("critical message")

$ python simple_logging_module.py 2005-03-19 15:10:26,618 - simple_example - DEBUG - debug message 2005-03-19 15:10:26,620 - simple_example - INFO - info message 2005-03-19 15:10:26,695 - simple_example - WARNING - warn message 2005-03-19 15:10:26,697 - simple_example - ERROR - error message 2005-03-19 15:10:26,773 - simple_example - CRITICAL - critical message

import logging # set up logging to file - see previous section for more details logging.basicConfig(level=logging.DEBUG,                     format='%(asctime)s %(name)-12s %(levelname)-8s %(message)s',                     datefmt='%m-%d %H:%M',                     filename='/temp/myapp.log',                     filemode='w') # define a Handler which writes INFO messages or higher to the sys.stderr console = logging.StreamHandler() console.setLevel(logging.INFO) # set a format which is simpler for console use formatter = logging.Formatter('%(name)-12s: %(levelname)-8s %(message)s') # tell the handler to use this format console.setFormatter(formatter) # add the handler to the root logger logging.getLogger('').addHandler(console) # Now, we can log to the root logger, or any other logger. First the root... logging.info('Jackdaws love my big sphinx of quartz.') # Now, define a couple of other loggers which might represent areas in your # application: logger1 = logging.getLogger('myapp.area1') logger2 = logging.getLogger('myapp.area2') logger1.debug('Quick zephyrs blow, vexing daft Jim.') logger1.info('How quickly daft jumping zebras vex.') logger2.warning('Jail zesty vixen who grabbed pay from quack.') logger2.error('The five boxing wizards jump quickly.')

root        : INFO     Jackdaws love my big sphinx of quartz. myapp.area1 : INFO     How quickly daft jumping zebras vex. myapp.area2 : WARNING  Jail zesty vixen who grabbed pay from quack. myapp.area2 : ERROR    The five boxing wizards jump quickly.

10-22 22:19 root         INFO     Jackdaws love my big sphinx of quartz. 10-22 22:19 myapp.area1  DEBUG    Quick zephyrs blow, vexing daft Jim. 10-22 22:19 myapp.area1  INFO     How quickly daft jumping zebras vex. 10-22 22:19 myapp.area2  WARNING  Jail zesty vixen who grabbed pay from quack. 10-22 22:19 myapp.area2  ERROR    The five boxing wizards jump quickly.