python常用模块-logging

butter7372

　　Logging 模块
　　很多程序都有记录日志的需求并且日志中包含的信息即有正常的程序访问日志还可能有错误、警告等信息输出python的logging模块提供了标准的日志接口你可以通过它存储各种格式的日志logging的日志可以分为 debug(), info(), warning(), error() and critical() 5个级别下面我们看一下怎么用。
　　最简单用法
12345678import logging logging.warning("user [alex] attempted wrong password more than 3 times")logging.critical("server is down") #输出WARNING:root:user [alex] attempted wrong password more than 3 timesCRITICAL:root:server is down　　看一下这几个日志级别分别代表什么意思
LevelWhen it’s usedDEBUGDetailed information, typically of interest only when diagnosing problems.INFOConfirmation that things are working as expected.WARNINGAn indication that something unexpected happened, or indicative of some problem in the near future (e.g. ‘disk space low’). The software is still working as expected.ERRORDue to a more serious problem, the software has not been able to perform some function.CRITICALA serious error, indicating that the program itself may be unable to continue running.　　如果想把日志写到文件里也很简单
123456import logging logging.basicConfig(filename='example.log',level=logging.INFO) logging.debug('This message should go to the log file')logging.info('So should this')logging.warning('And this, too')　　其中下面这句中的level=loggin.INFO意思是把日志纪录级别设置为INFO也就是说只有比日志是INFO或比INFO级别更高 的日志才会被纪录到文件里在这个例子 第一条日志是不会被纪录的如果希望纪录debug的日志那把日志级别改成DEBUG就行了。
1logging.basicConfig(filename='example.log',level=logging.INFO)　　感觉上面的日志格式忘记加上时间啦日志不知道时间怎么行呢下面就来加上!
123456import logginglogging.basicConfig(format='%(asctime)s %(message)s', datefmt='%m/%d/%Y %I:%M:%S %p')logging.warning('is when this event was logged.') #输出12/12/2010 11:46:36 AM is when this event was logged.