python中的日志级别

Python按照重要程度把日志分为5个级别，如下：

可以通过level参数，设置不同的日志级别。当设置为高的日志级别时，低于此级别的日志不再打印。

五种日志级别按从低到高排序：

　　DEBUG < INFO < WARNING < ERROR < CRITICAL

1. level设置为DEBUG级别，所有的日志都会打印

import logging
logging.basicConfig(level=logging.DEBUG, format=' %(asctime)s - %(levelname)s -%(message)s')
logging.debug('Some debugging details.')
logging.info('The logging module is working')
logging.warning('An error message is about to be logged.')
logging.error('An error has occurred.')
logging.critical('The program is unable to recover!')

 2019-11-17 15:24:30,065 - DEBUG -Some debugging details.
 2019-11-17 15:24:30,074 - INFO -The logging module is working
 2019-11-17 15:24:30,086 - WARNING -An error message is about to be logged.
 2019-11-17 15:24:30,105 - ERROR -An error has occurred.
 2019-11-17 15:24:30,107 - CRITICAL -The program is unable to recover!

2. level设置为ERROR级别时，只显示ERROR和CRITICAL日志

import logging
logging.basicConfig(level=logging.ERROR, format=' %(asctime)s - %(levelname)s -%(message)s')
logging.debug('Some debugging details.')
logging.info('The logging module is working')
logging.warning('An error message is about to be logged.')
logging.error('An error has occurred.')
logging.critical('The program is unable to recover!')

 2019-11-17 15:30:46,767 - ERROR -An error has occurred.
 2019-11-17 15:30:46,768 - CRITICAL -The program is unable to recover!