python logging日志模块的详解

日志一共分成5个等级，从低到高分别是：DEBUG INFO WARNING ERROR CRITICAL。DEBUG：详细的信息,通常只出现在诊断问题上INFO：确认一切按预期运行WARNING：一个迹象表明,一些意想不到的事情发生了,或表明一些问题在不久的将来(例如。磁盘空间低”)。这个软件还能按预期工作。ERROR：更严重的问题,软件没能执行一些功能CRITICAL：一个严重的错误,这表明程序本身可能无法继续运行这5个等级，也分别对应5种打日志的方法： debug 、info 、warning 、error 、critical。默认的是WARNING，当在WARNING或之上时才被跟踪。

logging.basicConfig函数中，可以指定日志的输出格式format，这个参数可以输出很多有用的信息，如上例所示：%(levelno)s: 打印日志级别的数值%(levelname)s: 打印日志级别名称%(pathname)s: 打印当前执行程序的路径，其实就是sys.argv[0]%(filename)s: 打印当前执行程序名%(funcName)s: 打印日志的当前函数%(lineno)d: 打印日志的当前行号%(asctime)s: 打印日志的时间%(thread)d: 打印线程ID%(threadName)s: 打印线程名称%(process)d: 打印进程ID%(message)s: 打印日志信息我在工作中给的常用格式在前面已经看到了。就是：format='%(asctime)s - %(filename)s[line:%(lineno)d] - %(levelname)s: %(message)s'这个格式可以输出日志的打印时间，是哪个模块输出的，输出的日志级别是什么，以及输入的日志内容。

import logging logging.basicConfig(level=logging.WARNING,           format='%(asctime)s - %(filename)s[line:%(lineno)d] - %(levelname)s: %(message)s') # use logging logging.info('this is a loggging info message') logging.debug('this is a loggging debug message') logging.warning('this is loggging a warning message') logging.error('this is an loggging error message') logging.critical('this is a loggging critical message') 执行上面的代码将在Console中输出下面信息：2017-03-16 16:58:11,266 - a.py[line:10] - WARNING: this is loggging a warning message2017-03-16 16:58:11,266 - a.py[line:11] - ERROR: this is an loggging error message2017-03-16 16:58:11,266 - a.py[line:12] - CRITICAL: this is a loggging critical message

import logging logging.basicConfig(level=logging.WARNING,           filename='./log/log.txt',           filemode='w',           format='%(asctime)s - %(filename)s[line:%(lineno)d] - %(levelname)s: %(message)s') # use logging logging.info('this is a loggging info message') logging.debug('this is a loggging debug message') logging.warning('this is loggging a warning message') logging.error('this is an loggging error message') logging.critical('this is a loggging critical message') 运行之后，打开该文件./log/log.txt，效果如下：2015-05-21 17:30:20,282 - log.py[line:12] - WARNING: this is loggging a warning message2015-05-21 17:30:20,282 - log.py[line:13] - ERROR: this is an loggging error message2015-05-21 17:30:20,282 - log.py[line:14] - CRITICAL: this is a loggging critical message

#config.conf###############################################[loggers]keys=root,example01,example02[logger_root]level=DEBUGhandlers=hand01,hand02[logger_example01]handlers=hand01,hand02qualname=example01propagate=0[logger_example02]handlers=hand01,hand03qualname=example02propagate=0###############################################[handlers]keys=hand01,hand02,hand03[handler_hand01]class=StreamHandlerlevel=INFOformatter=form02args=(sys.stderr,)[handler_hand02]class=FileHandlerlevel=NOTSETformatter=form01args=('myapp.log', 'a')[handler_hand03]class=handlers.RotatingFileHandlerlevel=INFOformatter=form02args=('myapp.log', 'a', 10*1024*1024, 5)###############################################[formatters]keys=form01,form02[formatter_form01]format=%(asctime)s %(filename)s[line:%(lineno)d] %(levelname)s %(message)sdatefmt=%a, %d %b %Y %H:%M:%S[formatter_form02]format=%(name)-12s: %(levelname)-8s %(message)sdatefmt=

import loggingimport logging.configlogging.config.fileConfig("/home/razerware/configscript/config.conf")logger = logging.getLogger("example01")logger2 = logging.getLogger("example02")logger.debug('This is debug message')logger.info('This is info message')logger.warning('This is warning message')logger2.debug('This is debug message')logger2.info('This is info message')logger2.warning('This is warning message')