1.簡(jiǎn)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(rèn)情況下，logging將日志打印到屏幕，日志級(jí)別為WARNING；
日志級(jí)別大小關(guān)系為：CRITICAL > ERROR > WARNING > INFO > DEBUG > NOTSET，當(dāng)然也可以自己定義日志級(jí)別。
2.通過(guò)logging.basicConfig函數(shù)對(duì)日志的輸出格式及方式做相關(guān)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文件中內(nèi)容為:
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函數(shù)各參數(shù):
filename: 指定日志文件名
filemode: 和file函數(shù)意義相同，指定日志文件的打開(kāi)模式，'w'或'a'
format: 指定輸出的格式和內(nèi)容，format可以輸出很多有用信息，如上例所示:
%(levelno)s: 打印日志級(jí)別的數(shù)值
%(levelname)s: 打印日志級(jí)別名稱(chēng)
%(pathname)s: 打印當(dāng)前執(zhí)行程序的路徑，其實(shí)就是sys.argv[0]
%(filename)s: 打印當(dāng)前執(zhí)行程序名
%(funcName)s: 打印日志的當(dāng)前函數(shù)
%(lineno)d: 打印日志的當(dāng)前行號(hào)
%(asctime)s: 打印日志的時(shí)間
%(thread)d: 打印線程ID
%(threadName)s: 打印線程名稱(chēng)
%(process)d: 打印進(jìn)程ID
%(message)s: 打印日志信息
datefmt: 指定時(shí)間格式，同time.strftime()
level: 設(shè)置日志級(jí)別，默認(rèn)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(rèn)輸出到sys.stderr，當(dāng)stream和filename同時(shí)指定時(shí)，stream被忽略
3.將日志同時(shí)輸出到文件和屏幕
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')
定義一個(gè)StreamHandler，將INFO級(jí)別或更高的日志信息打印到標(biāo)準(zhǔn)錯(cuò)誤，并將其添加到當(dāng)前的日志處理對(duì)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文件中內(nèi)容為:
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之日志回滾
import logging
from logging.handlers import RotatingFileHandler
定義一個(gè)RotatingFileHandler，最多備份5個(gè)日志文件，每個(gè)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)
從上例和本例可以看出，logging有一個(gè)日志處理的主對(duì)象，其它處理方式都是通過(guò)addHandler添加進(jìn)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(shí)際使用時(shí)用RotatingFileHandler和TimedRotatingFileHandler
logging.handlers.BaseRotatingHandler
logging.handlers.RotatingFileHandler
logging.handlers.TimedRotatingFileHandler
logging.handlers.SocketHandler: 遠(yuǎn)程輸出日志到TCP/IP sockets
logging.handlers.DatagramHandler: 遠(yuǎn)程輸出日志到UDP sockets
logging.handlers.SMTPHandler: 遠(yuǎn)程輸出日志到郵件地址
logging.handlers.SysLogHandler: 日志輸出到syslog
logging.handlers.NTEventLogHandler: 遠(yuǎn)程輸出日志到Windows NT/2000/XP的事件日志
logging.handlers.MemoryHandler: 日志輸出到內(nèi)存中的制定buffer
logging.handlers.HTTPHandler: 通過(guò)"GET"或"POST"遠(yuǎn)程輸出到HTTP服務(wù)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，
上述其它處理方式的使用請(qǐng)參見(jiàn)python2.5手冊(cè)！
5.通過(guò)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=
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')
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是線程安全的
