python 的日志logging模块学习
1.简单的将日志打印到屏幕
import logging logging.debug('This is debug message') logging.info('This is info message') logging.warning('This is warning message')
屏幕上打印:
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;
日志级别大小关系为:CRITICAL > ERROR > WARNING > INFO > DEBUG > NOTSET,当然也可以自己定义日志级别。
2.通过logging.basicConfig函数对日志的输出格式及方式做相关配置
import logging logging.basicConfig(level=logging.DEBUG, format='%(asctime)s %(filename)s[line:%(lineno)d] %(levelname)s %(message)s', datefmt='%a, %d %b %Y %H:%M:%S', filename='myapp.log', filemode='w') logging.debug('This is debug message') logging.info('This is info message') logging.warning('This is warning message')
./myapp.log文件中内容为:
Sun, 24 May 2009 21:48:54 demo2.py[line:11] DEBUG This is debug message
Sun, 24 May 2009 21:48:54 demo2.py[line:12] INFO This is info message
Sun, 24 May 2009 21:48:54 demo2.py[line:13] WARNING This is warning message
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.WARNING
stream: 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
#coding=utf-8 import logging logging.basicConfig(level=logging.DEBUG, format='%(asctime)s %(filename)s[line:%(lineno)d] %(levelname)s %(message)s', datefmt='%a, %d %b %Y %H:%M:%S', filename='myapp.log', filemode='w') #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) 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 message
root : WARNING This is warning message
./myapp.log文件中内容为:
Sun, 24 May 2009 21:48:54 demo2.py[line:11] DEBUG This is debug message
Sun, 24 May 2009 21:48:54 demo2.py[line:12] INFO This is info message
Sun, 24 May 2009 21:48:54 demo2.py[line:13] WARNING This is warning message
4.logging之日志回滚
#coding=utf-8 import logging from 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10M Rthandler = RotatingFileHandler('myapp.log', maxBytes=10*1024*1024,backupCount=5) Rthandler.setLevel(logging.INFO) formatter = logging.Formatter('%(name)-12s: %(levelname)-8s %(message)s') Rthandler.setFormatter(formatter) logging.getLogger('').addHandler(Rthandler)
从上例和本例可以看出,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的几种handle方式如下:
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TimedRotatingFileHandler
logging.handlers.BaseRotatingHandler
logging.handlers.RotatingFileHandler
logging.handlers.TimedRotatingFileHandler
logging.handlers.SocketHandler: 远程输出日志到TCP/IP sockets
logging.handlers.DatagramHandler: 远程输出日志到UDP sockets
logging.handlers.SMTPHandler: 远程输出日志到邮件地址
logging.handlers.SysLogHandler: 日志输出到syslog
logging.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buffer
logging.handlers.HTTPHandler: 通过"GET"或"POST"远程输出到HTTP服务器
由于StreamHandler和FileHandler是常用的日志处理方式,所以直接包含在logging模块中,而其他方式则包含在logging.handlers模块中,
上述其它处理方式的使用请参见python2.5手册!
5.通过logging.config模块配置日志
#coding=utf-8 #logger.conf ############################################### [loggers] keys=root,example01,example02 [logger_root] level=DEBUG handlers=hand01,hand02 [logger_example01] handlers=hand01,hand02 qualname=example01 propagate=0 [logger_example02] handlers=hand01,hand03 qualname=example02 propagate=0 ############################################### [handlers] keys=hand01,hand02,hand03 [handler_hand01] class=StreamHandler level=INFO formatter=form02 args=(sys.stderr,) [handler_hand02] class=FileHandler level=DEBUG formatter=form01 args=('myapp.log', 'a') [handler_hand03] class=handlers.RotatingFileHandler level=INFO formatter=form02 args=('myapp.log', 'a', 10*1024*1024, 5) ############################################### [formatters] keys=form01,form02 [formatter_form01] format=%(asctime)s %(filename)s[line:%(lineno)d] %(levelname)s %(message)s datefmt=%a, %d %b %Y %H:%M:%S [formatter_form02] format=%(name)-12s: %(levelname)-8s %(message)s datefmt=
上例3:
import logging import logging.config logging.config.fileConfig("logger.conf") logger = logging.getLogger("example01") logger.debug('This is debug message') logger.info('This is info message') logger.warning('This is warning message')
上例4:
import logging import logging.config logging.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')