Logging properly in Python

Introduction

It is also for myself.

code

`main.py`


#!/usr/bin/env python
# -*- coding: utf-8 -*-

import logging
import othermodule

LOG_LEVEL = 'DEBUG'

if __name__ == '__main__':

    logging.basicConfig(
        level=getattr(logging, LOG_LEVEL),
        format='%(asctime)s [%(levelname)s] %(module)s | %(message)s',
        datefmt='%Y/%m/%d %H:%M:%S',
    )

    # test
    logger = logging.getLogger(__name__)
    logger.critical('critical message')
    logger.error('error message')
    logger.warning('warning message')
    logger.info('info message')
    logger.debug('debug message')
    othermodule.test()

`othermodule.py`


#!/usr/bin/env python
# -*- coding: utf-8 -*-

import logging

def test():
    _logger = logging.getLogger(__name__)
    _logger.critical('critical message')
    _logger.error('error message')
    _logger.warning('warning message')
    _logger.info('info message')
    _logger.debug('debug message')

$ python main.py
2017/01/01 00:00:00 [CRITICAL] main | critical message
2017/01/01 00:00:00 [ERROR] main | error message
2017/01/01 00:00:00 [WARNING] main | warning message
2017/01/01 00:00:00 [DEBUG] main | info message
2017/01/01 00:00:00 [INFO] main | debug message
2017/01/01 00:00:00 [CRITICAL] othermodule | critical message
2017/01/01 00:00:00 [ERROR] othermodule | error message
2017/01/01 00:00:00 [WARNING] othermodule | warning message
2017/01/01 00:00:00 [DEBUG] othermodule | info message
2017/01/01 00:00:00 [INFO] othermodule | debug message

Description Other

--level = getattr (logging, LOG_LEVEL)Assuming that the log level is set from the character string obtained from config etc. --If you use logging # debug or something, it will not be divided by module and you will be hit by the root logger, so use logging # getLogger to get the appropriate logger properly. --If you set the root logger with logging # basicConfig, you can also set the logger of the module used by import at once. --If you do not logging # basicConfig, StreamHandler (handler that outputs log to standard output) will not be generated and will not be output to the console.

attribute	Description
`%(asctime)s`	`datefmt`Log generation time according to
`%(levelname)s`	Log level name
`%(module)s`	Module name
`%(message)s`	Log message