Python logging模塊使用記錄
1.簡單的將日志打印到屏幕
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
默認情況下,logging將日志打印到屏幕,日志級別為WARNING;
日志級別大小關系為:CRITICAL > ERROR > WARNING > INFO > DEBUG > NOTSET,當然也可以自己定義日志級別。
2.通過logging.basicConfig函數對日志的輸出格式及方式做相關配置
1 import logging 2 3 logging.basicConfig(level=logging.DEBUG, 4 format='%(asctime)s %(filename)s[line:%(lineno)d] %(levelname)s %(message)s', 5 datefmt='%a, %d %b %Y %H:%M:%S', 6 filename='myapp.log', 7 filemode='w') 8 9 logging.debug('This is debug message') 10 logging.info('This is info message') 11 logging.warning('This is warning message') 12 13 ./myapp.log文件中內容為: 14 Sun, 24 May 2009 21:48:54 demo2.py[line:11] DEBUG This is debug message 15 Sun, 24 May 2009 21:48:54 demo2.py[line:12] INFO This is info message 16 Sun, 24 May 2009 21:48:54 demo2.py[line:13] WARNING This is warning message
logging.basicConfig函數各參數:
filename: 指定日志文件名
filemode: 和file函數意義相同,指定日志文件的打開模式,'w'或'a'
format: 指定輸出的格式和內容,format可以輸出很多有用信息,如上例所示:
%(levelno)s: 打印日志級別的數值
%(levelname)s: 打印日志級別名稱
%(pathname)s: 打印當前執行程序的路徑,其實就是sys.argv[0]
%(filename)s: 打印當前執行程序名
%(funcName)s: 打印日志的當前函數
%(lineno)d: 打印日志的當前行號
%(asctime)s: 打印日志的時間
%(thread)d: 打印線程ID
%(threadName)s: 打印線程名稱
%(process)d: 打印進程ID
%(message)s: 打印日志信息
datefmt: 指定時間格式,同time.strftime()
level: 設置日志級別,默認為logging.WARNING
stream: 指定將日志的輸出流,可以指定輸出到sys.stderr,sys.stdout或者文件,默認輸出到sys.stderr,當stream和filename同時指定時,stream被忽略
3.將日志同時輸出到文件和屏幕
1 import logging 2 3 logging.basicConfig(level=logging.DEBUG, 4 format='%(asctime)s %(filename)s[line:%(lineno)d] %(levelname)s %(message)s', 5 datefmt='%a, %d %b %Y %H:%M:%S', 6 filename='myapp.log', 7 filemode='w') 8 9 ################################################################################################# 10 #定義一個StreamHandler,將INFO級別或更高的日志信息打印到標準錯誤,并將其添加到當前的日志處理對象# 11 console = logging.StreamHandler() 12 console.setLevel(logging.INFO) 13 formatter = logging.Formatter('%(name)-12s: %(levelname)-8s %(message)s') 14 console.setFormatter(formatter) 15 logging.getLogger('').addHandler(console) 16 ################################################################################################# 17 18 logging.debug('This is debug message') 19 logging.info('This is info message') 20 logging.warning('This is warning message') 21 22 屏幕上打印: 23 root : INFO This is info message 24 root : WARNING This is warning message 25 ./myapp.log文件中內容為: 26 Sun, 24 May 2009 21:48:54 demo2.py[line:11] DEBUG This is debug message 27 Sun, 24 May 2009 21:48:54 demo2.py[line:12] INFO This is info message 28 Sun, 24 May 2009 21:48:54 demo2.py[line:13] WARNING This is warning message
4.logging之日志回滾
1 import logging 2 from logging.handlers import RotatingFileHandler 3 4 ################################################################################################# 5 #定義一個RotatingFileHandler,最多備份5個日志文件,每個日志文件最大10M 6 Rthandler = RotatingFileHandler('myapp.log', maxBytes=10*1024*1024,backupCount=5) 7 Rthandler.setLevel(logging.INFO) 8 formatter = logging.Formatter('%(name)-12s: %(levelname)-8s %(message)s') 9 Rthandler.setFormatter(formatter) 10 logging.getLogger('').addHandler(Rthandler) 11 ################################################################################################
從上例和本例可以看出,logging有一個日志處理的主對象,其它處理方式都是通過addHandler添加進去的。
logging的幾種handle方式如下:
logging.StreamHandler: 日志輸出到流,可以是sys.stderr、sys.stdout或者文件
logging.FileHandler: 日志輸出到文件
日志回滾方式,實際使用時用RotatingFileHandler和TimedRotatingFileHandler
logging.handlers.BaseRotatingHandler
logging.handlers.RotatingFileHandler
logging.handlers.TimedRotatingFileHandler
logging.handlers.SocketHandler: 遠程輸出日志到TCP/IP sockets
logging.handlers.DatagramHandler: 遠程輸出日志到UDP sockets
logging.handlers.SMTPHandler: 遠程輸出日志到郵件地址
logging.handlers.SysLogHandler: 日志輸出到syslog
logging.handlers.NTEventLogHandler: 遠程輸出日志到Windows NT/2000/XP的事件日志
logging.handlers.MemoryHandler: 日志輸出到內存中的制定buffer
logging.handlers.HTTPHandler: 通過"GET"或"POST"遠程輸出到HTTP服務器
由于StreamHandler和FileHandler是常用的日志處理方式,所以直接包含在logging模塊中,而其他方式則包含在logging.handlers模塊中,
5.通過logging.config模塊配置日志
#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')

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