快捷導(dǎo)航

Python logging模塊學(xué)習(xí)筆記

更新時(shí)間：2014年05月24日 16:09:03 作者：

這篇文章主要介紹了Python logging模塊,logging模塊是在2.3新引進(jìn)的功能,用來(lái)處理程序運(yùn)行中的日志管理,本文詳細(xì)講解了該模塊的一些常用的類(lèi)和模塊級(jí)函數(shù),需要的朋友可以參考下

模塊級(jí)函數(shù)

logging.getLogger([name]):返回一個(gè)logger對(duì)象，如果沒(méi)有指定名字將返回root logger
logging.debug()、logging.info()、logging.warning()、logging.error()、logging.critical()：設(shè)定root logger的日志級(jí)別
logging.basicConfig():用默認(rèn)Formatter為日志系統(tǒng)建立一個(gè)StreamHandler，設(shè)置基礎(chǔ)配置并加到root logger中

示例：logging_level_example.py

復(fù)制代碼代碼如下:

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')

輸出：

復(fù)制代碼代碼如下:

$ 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):指定最低的日志級(jí)別，低于lel的級(jí)別將被忽略。debug是最低的內(nèi)置級(jí)別，critical為最高
Logger.addFilter(filt)、Logger.removeFilter(filt):添加或刪除指定的filter
Logger.addHandler(hdlr)、Logger.removeHandler(hdlr)：增加或刪除指定的handler
Logger.debug()、Logger.info()、Logger.warning()、Logger.error()、Logger.critical()：可以設(shè)置的日志級(jí)別

示例：simple_logging_module.py

復(fù)制代碼代碼如下:

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")

輸出：

復(fù)制代碼代碼如下:

$ 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對(duì)象負(fù)責(zé)發(fā)送相關(guān)的信息到指定目的地?？梢酝ㄟ^(guò)addHandler()方法添加多個(gè)多handler
Handler.setLevel(lel):指定被處理的信息級(jí)別，低于lel級(jí)別的信息將被忽略
Handler.setFormatter()：給這個(gè)handler選擇一個(gè)格式
Handler.addFilter(filt)、Handler.removeFilter(filt)：新增或刪除一個(gè)filter對(duì)象

Formatters

Formatter對(duì)象設(shè)置日志信息最后的規(guī)則、結(jié)構(gòu)和內(nèi)容，默認(rèn)的時(shí)間格式為%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	數(shù)字形式的日志級(jí)別
%(levelname)s	文本形式的日志級(jí)別
%(pathname)s	調(diào)用日志輸出函數(shù)的模塊的完整路徑名，可能沒(méi)有
%(filename)s	調(diào)用日志輸出函數(shù)的模塊的文件名
%(module)s	調(diào)用日志輸出函數(shù)的模塊名
%(funcName)s	調(diào)用日志輸出函數(shù)的函數(shù)名
%(lineno)d	調(diào)用日志輸出函數(shù)的語(yǔ)句所在的代碼行
%(created)f	當(dāng)前時(shí)間，用UNIX標(biāo)準(zhǔn)的表示時(shí)間的浮點(diǎn)數(shù)表示
%(relativeCreated)d	輸出日志信息時(shí)的，自L(fǎng)ogger創(chuàng)建以來(lái)的毫秒數(shù)
%(asctime)s	字符串形式的當(dāng)前時(shí)間。默認(rèn)格式是 “2003-07-08 16:49:45,896”。逗號(hào)后面的是毫秒
%(thread)d	線(xiàn)程ID?？赡軟](méi)有
%(threadName)s	線(xiàn)程名?？赡軟](méi)有
%(process)d	進(jìn)程ID?？赡軟](méi)有
%(message)s	用戶(hù)輸出的消息

最后來(lái)個(gè)完整例子：

復(fù)制代碼代碼如下:

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.')

運(yùn)行后，在終端看到的結(jié)果

復(fù)制代碼代碼如下:

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.

在日志文件中的結(jié)果

復(fù)制代碼代碼如下:

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.

發(fā)現(xiàn)DEBUG信息只有在文件中出現(xiàn)，這是因?yàn)镾treamHandler中setLevel是INFO，可以看出Logger.setLevel()和handler.setLevel()的區(qū)別

詳細(xì)信息請(qǐng)參閱 http://docs.python.org/library/logging.html

您可能感興趣的文章: