python之强大的日志模块【转】

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

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

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python 2.5手册！

5.通过logging.config模块配置日志

# 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' )

6.logging是线程安全的

 

 

转至: http://hi.baidu.com/victoryz/blog/item/9974dd16f9475159f2de3251.html