Python logging模块

Good logging practice in Python

这篇介绍地不错，由浅入深

http://victorlin.me/posts/2012/08/26/good-logging-practice-in-python

There are different handlers, you can also send records to you mailbox or even a to a remote server. You can also write your own custom logging handler. I’m not going to tell you details, please reference to official documents: Basic Tutorial, Advanced Tutorial and Logging Cookbook.

通过配置设置日志格式

import logging
import logging.config

logging.config.fileConfig('logging.conf')

# create logger
logger = logging.getLogger('simpleExample')

# 'application' code
logger.debug('debug message')
logger.info('info message')
logger.warn('warn message')
logger.error('error message')
logger.critical('critical message')

　　

配置文件：

[loggers]
keys=root,simpleExample

[handlers]
keys=consoleHandler

[formatters]
keys=simpleFormatter

[logger_root]
level=DEBUG
handlers=consoleHandler

[logger_simpleExample]
level=DEBUG
handlers=consoleHandler
qualname=simpleExample
propagate=0

[handler_consoleHandler]
class=StreamHandler
level=DEBUG
formatter=simpleFormatter
args=(sys.stdout,)

[formatter_simpleFormatter]
format=%(asctime)s - %(name)s - %(levelname)s - %(message)s
datefmt=

Use _name_ as the logger name

根据调用的模块生成相关日志，日志中记录调用的模块名称

guosongdeMacBook-Air:20150114 guosong$ tree |grep -v pyc
.
├── main.py
├── test
│   ├── __init__.py
│   ├── test.py
└── test.test

1 directory, 6 files
guosongdeMacBook-Air:20150114 guosong$ ./main.py
guosongdeMacBook-Air:20150114 guosong$ ll
total 16
-rwxr-xr-x  1 guosong  staff   136B  1 14 11:48 main.py
drwxr-xr-x  6 guosong  staff   204B  1 14 11:51 test
-rw-r--r--  1 guosong  staff   336B  1 14 11:53 test.test
guosongdeMacBook-Air:20150114 guosong$ more test.test
2015-01-14 11:51:26,373 - test.test - INFO - Hello baby
2015-01-14 11:51:26,374 - test.test - INFO - Hello baby
2015-01-14 11:51:26,374 - test.test - INFO - Hello baby
2015-01-14 11:53:09,950 - test.test - INFO - Hello baby
2015-01-14 11:53:09,951 - test.test - INFO - Hello baby
2015-01-14 11:53:09,951 - test.test - INFO - Hello baby

　　

　　

　　

http://blog.donews.com/limodou/archive/2005/02/16/278699.aspx

#!/usr/bin/env python

import logging

logfile="./log.file"

def initlog():
        logger=logging.getLogger()
        hdlr=logging.FileHandler(logfile)

        formatter=logging.Formatter('%(asctime)s %(levelname)s %(message)s')
        hdlr.setFormatter(formatter)
        logger.addHandler(hdlr)
        logger.setLevel(logging.NOTSET)

        return logger

def main():
        logger=initlog()

        message="error"
        logger.error(message)

        message="info"
        logger.info(message)

if __name__ == "__main__":
        main()

第8行生成一个日志对象，可以带一个名字，可以缺省。
第9行生成一个Handler。logging支持许多Handler，象FileHandler, SocketHandler, SMTPHandler等，我由于要写文件就使用了FileHandler。logfile是一个全局变量，它就是一个文件名，如：’crawl.log’。
第11行生成一个格式器，用于规范日志的输出格式。如果没有这行代码，那么缺省的格式就是：”%(message)s”。也就是写日志时，信息是什么日志中就是什么，没有日期，没有信息级别等信息。logging支持许多种替换值，详细请看Formatter的文档说明。这里有三项：时间，信息级别，日志信息。
第12行将格式器设置到处理器上。
第13行将处理器加到日志对象上。
第14行设置日志信息输出的级别。logging提供多种级别的日志信息，如：NOTSET, DEBUG, INFO, WARNING, ERROR, CRITICAL等。每个级别都对应一个数值。如果不执行此句，缺省为30(WARNING)。可以执行：logging.getLevelName(logger.getEffectiveLevel())来查看缺省的日志级别。日志对象对于不同的级别信息提供不同的函数进行输出，如：info(), error(), debug()等。当写入日志时，小于指定级别的信息将被忽略。因此为了输出想要的日志级别一定要设置好此参数。这里我设为NOTSET（值为0），也就是想输出所有信息。

getLogger两个方法：

1、getLogger(name=None)

Return a logger with the specified name, creating it if necessary.
If no name is specified, return the root logger.

2、getLogger(self, name)

| Get a logger with the specified name (channel name), creating it
| if it doesn't yet exist. This name is a dot-separated hierarchical
| name, such as "a", "a.b", "a.b.c" or similar.
|
| If a PlaceHolder existed for the specified name [i.e. the logger
| didn't exist but a child of it did], replace it with the created
| logger and fix up the parent/child references which pointed to the
| placeholder to now point to the logger.

封装的日志：

#!/usr/bin/python26
#-*- coding:utf8 -*-

import os
import sys
import logging
import logging.handlers

#解决路径问题
os.chdir(sys.path[0])

class Logger(object):
        def __init__(self,log_dir,log_level,logger_name):
                if not os.path.exists(log_dir):
                        os.mkdir(log_dir)
                self.__log_filename = log_dir + logger_name + ".log"

                self.__logger = logging.getLogger(logger_name)
                self.__logger.setLevel(log_level)

                handler = logging.handlers.RotatingFileHandler(self.__log_filename,maxBytes=10000,backupCount=0)

                formatter = logging.Formatter("%(asctime)s - [%(levelname)s] [%(name)s/%(filename)s %(lineno)d] - %(message)s")

                handler.setFormatter(formatter)
                self.__logger.addHandler(handler)

        def debug(self,message):
                self.__logger.debug(message)

        def error(self,message):
                self.__logger.error(message)

        def info(self,message):
                self.__logger.info(message)

def main():
        logger = Logger("../log/",logging.DEBUG,"test")
        logger.debug("Test")

if __name__ == '__main__':
        main()