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1.打印到屏幕

import logging logging.debug('This is debug message')logging.info('This is info message')logging.warning('This is warning message')

打印输出：

WARNING:root:This is warning message

默认情况下，logging将日志打印到屏幕，日志级别为WARNING；

2.配置格式和输出方式

import logging logging.basicConfig(level=logging.DEBUG,#日志级别                    format='%(asctime)s %(filename)s[line:%(lineno)d] %(levelname)s %(message)s',#日志格式                    filename='myapp.log',#日志文件名                    filemode='a'#r 只读 w可写 a追加                    )logging.debug('This is debug message')logging.info('This is info message')logging.warning('This is warning message')

属性说明：

logging.basicConfig函数各参数:filename: 指定日志文件名filemode: 和file函数意义相同，指定日志文件的打开模式，'w'或'a'format: 指定输出的格式和内容，format可以输出很多有用信息，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datefmt: 指定时间格式，同time.strftime()level: 设置日志级别，默认为logging.WARNINGstream: 指定将日志的输出流，可以指定输出到sys.stderr,sys.stdout或者文件，默认输出到sys.stderr，当stream和filename同时指定时，stream被忽略

3.将日志同时输出到文件和屏幕

import logging logging.basicConfig(level=logging.DEBUG,                    format='%(asctime)s %(filename)s[line:%(lineno)d] %(levelname)s %(message)s',                    filename='myapp.log',                    filemode='a'                    )##################################################################################################定义一个StreamHandler，将INFO级别或更高的日志信息打印到标准错误，并将其添加到当前的日志处理对象#console = logging.StreamHandler()console.setLevel(logging.INFO)#INFO级别formatter = logging.Formatter('%(name)-12s: %(levelname)-8s %(message)s')console.setFormatter(formatter)logging.getLogger('').addHandler(console)#################################################################################################logging.debug('This is debug message')logging.info('This is info message')logging.warning('This is warning message')

屏幕上打印:

root        : INFO     This is info messageroot        : WARNING  This is warning message

文件内容：

2017-03-30 11:14:30,433 log.py[line:27] DEBUG This is debug message2017-03-30 11:14:30,433 log.py[line:28] INFO This is info message2017-03-30 11:14:30,433 log.py[line:29] WARNING This is warning message

4.日志回滚

import loggingfrom logging.handlers import RotatingFileHandler##################################################################################################定义一个RotatingFileHandler，最多备份5个日志文件，每个日志文件最大10MRthandler = RotatingFileHandler("my.log",maxBytes=10*1024*1024,backupCount=5)Rthandler.setLevel(logging.INFO)formatter = logging.Formatter('%(name)-3s: %(levelname)-8s %(message)s')Rthandler.setFormatter(formatter)logging.getLogger('').addHandler(Rthandler)################################################################################################logging.debug('This is debug message')logging.info('This is info message')logging.warning('This is warning message')

logging有一个日志处理的主对象，其它处理方式都是通过addHandler添加进去的。

logging.StreamHandler: 日志输出到流，可以是sys.stderr、sys.stdout或者文件logging.FileHandler: 日志输出到文件日志回滚方式，实际使用时用RotatingFileHandler和TimedRotatingFileHandlerlogging.handlers.BaseRotatingHandlerlogging.handlers.RotatingFileHandlerlogging.handlers.TimedRotatingFileHandlerlogging.handlers.SocketHandler: 远程输出日志到TCP/IP socketslogging.handlers.DatagramHandler:  远程输出日志到UDP socketslogging.handlers.SMTPHandler:  远程输出日志到邮件地址logging.handlers.SysLogHandler: 日志输出到sysloglogging.handlers.NTEventLogHandler: 远程输出日志到Windows NT/2000/XP的事件日志logging.handlers.MemoryHandler: 日志输出到内存中的制定bufferlogging.handlers.HTTPHandler: 通过"GET"或"POST"远程输出到HTTP服务器

5.通过logging.config模块配置日志

#logger.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=DEBUGformatter=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("logger.conf")logger = logging.getLogger("example01") #输出到屏幕logger.debug('This is debug message')logger.info('This is info message')logger.warning('This is warning message')

import loggingimport logging.configlogging.config.fileConfig("logger.conf")logger = logging.getLogger("example02")logger.debug('This is debug message')logger.info('This is info message')logger.warning('This is warning message')

import loggingimport logging.configlogging.config.fileConfig("logger.conf")logger = logging.getLogger("root")logger.debug('This is debug message')logger.info('This is info message')logger.warning('This is warning message')

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