python 的日志logging模块

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

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python2.5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

from:http://blog.csdn.net/yatere/article/details/6655445

出处：http://www.cnblogs.com/dkblog/archive/2011/08/26/2155018.html

===========================================================================================

logging模块是在2.3新引进的功能，下面是一些常用的类和模块级函数

模块级函数

logging.getLogger([name]):返回一个logger对象，如果没有指定名字将返回root logger

logging.debug()、logging.info()、logging.warning()、logging.error()、logging.critical()：设定root logger的日志级别

logging.basicConfig():用默认Formatter为日志系统建立一个StreamHandler，设置基础配置并加到root logger中

import logging

import sys

LEVELS = {'debug': logging.DEBUG,

'info': logging.INFO,

'warning': logging.WARNING,

'error': logging.ERROR,

'critical': logging.CRITICAL}

if len(sys.argv) > 1:

level_name = sys.argv[1]

level = LEVELS.get(level_name, logging.NOTSET)

logging.basicConfig(level=level)

logging.debug('This is a debug message')

logging.info('This is an info message')

logging.warning('This is a warning message')

logging.error('This is an error message')

logging.critical('This is a critical error message')

$ python logging_level_example.py debug

DEBUG:root:This is a debug message

INFO:root:This is an info message

WARNING:root:This is a warning message

ERROR:root:This is an error message

CRITICAL:root:This is a critical error message

$ python logging_level_example.py info

INFO:root:This is an info message

WARNING:root:This is a warning message

ERROR:root:This is an error message

CRITICAL:root:This is a critical error message

Loggers

Logger.setLevel(lel):指定最低的日志级别，低于lel的级别将被忽略。debug是最低的内置级别，critical为最高

Logger.addFilter(filt)、Logger.removeFilter(filt):添加或删除指定的filter

Logger.addHandler(hdlr)、Logger.removeHandler(hdlr)：增加或删除指定的handler

Logger.debug()、Logger.info()、Logger.warning()、Logger.error()、Logger.critical()：可以设置的日志级别

import logging

# create logger

logger = logging.getLogger("simple_example")

logger.setLevel(logging.DEBUG)

# create console handler and set level to debug

ch = logging.StreamHandler()

ch.setLevel(logging.DEBUG)

# create formatter

formatter = logging.Formatter("%(asctime)s - %(name)s - %(levelname)s - %(message)s")

# add formatter to ch

ch.setFormatter(formatter)

# add ch to logger

logger.addHandler(ch)

# "application" code

logger.debug("debug message")

logger.info("info message")

logger.warn("warn message")

logger.error("error message")

logger.critical("critical message")

$ python simple_logging_module.py

2005-03-19 15:10:26,618 - simple_example - DEBUG - debug message

2005-03-19 15:10:26,620 - simple_example - INFO - info message

2005-03-19 15:10:26,695 - simple_example - WARNING - warn message

2005-03-19 15:10:26,697 - simple_example - ERROR - error message

2005-03-19 15:10:26,773 - simple_example - CRITICAL - critical message

Handlers

handler对象负责发送相关的信息到指定目的地。可以通过addHandler()方法添加多个多handler

Handler.setLevel(lel):指定被处理的信息级别，低于lel级别的信息将被忽略

Handler.setFormatter()：给这个handler选择一个格式

Handler.addFilter(filt)、Handler.removeFilter(filt)：新增或删除一个filter对象

Formatters

Formatter对象设置日志信息最后的规则、结构和内容，默认的时间格式为%Y-%m-%d %H:%M:%S，下面是Formatter常用的一些信息

%(name)s	Logger的名字
%(levelno)s	数字形式的日志级别
%(levelname)s	文本形式的日志级别
%(pathname)s	调用日志输出函数的模块的完整路径名，可能没有
%(filename)s	调用日志输出函数的模块的文件名
%(module)s	调用日志输出函数的模块名
%(funcName)s	调用日志输出函数的函数名
%(lineno)d	调用日志输出函数的语句所在的代码行
%(created)f	当前时间，用UNIX标准的表示时间的浮点数表示
%(relativeCreated)d	输出日志信息时的，自Logger创建以来的毫秒数
%(asctime)s	字符串形式的当前时间。默认格式是 “2003-07-08 16:49:45,896”。逗号后面的是毫秒
%(thread)d	线程ID。可能没有
%(threadName)s	线程名。可能没有
%(process)d	进程ID。可能没有
%(message)s	用户输出的消息

最后来个例子

import logging

# set up logging to file - see previous section for more details

logging.basicConfig(level=logging.DEBUG,

format='%(asctime)s %(name)-12s %(levelname)-8s %(message)s',

datefmt='%m-%d %H:%M',

filename='/temp/myapp.log',

filemode='w')

# define a Handler which writes INFO messages or higher to the sys.stderr

console = logging.StreamHandler()

console.setLevel(logging.INFO)

# set a format which is simpler for console use

formatter = logging.Formatter('%(name)-12s: %(levelname)-8s %(message)s')

# tell the handler to use this format

console.setFormatter(formatter)

# add the handler to the root logger

logging.getLogger('').addHandler(console)

# Now, we can log to the root logger, or any other logger. First the root...

logging.info('Jackdaws love my big sphinx of quartz.')

# Now, define a couple of other loggers which might represent areas in your

# application:

logger1 = logging.getLogger('myapp.area1')

logger2 = logging.getLogger('myapp.area2')

logger1.debug('Quick zephyrs blow, vexing daft Jim.')

logger1.info('How quickly daft jumping zebras vex.')

logger2.warning('Jail zesty vixen who grabbed pay from quack.')

logger2.error('The five boxing wizards jump quickly.')

运行后，在终端看到的结果

root        : INFO     Jackdaws love my big sphinx of quartz.

myapp.area1 : INFO     How quickly daft jumping zebras vex.

myapp.area2 : WARNING  Jail zesty vixen who grabbed pay from quack.

myapp.area2 : ERROR    The five boxing wizards jump quickly.

在日志文件中的结果

10-22 22:19 root         INFO     Jackdaws love my big sphinx of quartz.

10-22 22:19 myapp.area1  DEBUG    Quick zephyrs blow, vexing daft Jim.

10-22 22:19 myapp.area1  INFO     How quickly daft jumping zebras vex.

10-22 22:19 myapp.area2  WARNING  Jail zesty vixen who grabbed pay from quack.

10-22 22:19 myapp.area2  ERROR    The five boxing wizards jump quickly.

发现DEBUG信息只有在文件中出现，这是因为StreamHandler中setLevel是INFO，可以看出Logger.setLevel()和handler.setLevel()的区别

详细信息请参阅 http://docs.python.org/library/logging.html

出处：http://www.cnblogs.com/captain_jack/archive/2011/01/21/1941453.html#top