How to use Python's logging module

Several learning connections:

Official Python Link:

Https://docs.python.org/3.4/library/logging.html?highlight=logging

Translation (2.3 version only)

http://crazier9527.iteye.com/blog/290018

Another person's summary:

http://blog.csdn.net/fxjtoday/article/details/6307285

Best to understand, write the best:

Http://bbs.chinaunix.net/thread-3590256-1-1.html

My study summary is based on http://bbs.chinaunix.net/thread-3590256-1-1.html

Take a simple log system as an example to illustrate:

Goal: Create a log system that can not only output information to the console, but also output it to a file.

?

1234567891011121314151617181920212223242526272829

#import logging包import logging #创建一个logger,getLogger的参数是logger的名字logger=logging.getLogger(‘lylogger‘)#设置logger的等级，大于等于这个等级的信息会被输出，其他会被忽略logger.setLevel(logging.DEBUG) #Handler是英文翻译为处理者，用于输出到不同的地方：Stream为控制台，File为文件#以下创建的是输出到文件的handler，并把等级设为DEBUGfh=logging.FileHandler(‘test.log‘)fh.setLevel(logging.DEBUG) #以下创建的是输出到控制台的handler，并把等级设为DEBUGsh=logging.StreamHandler()sh.setLevel(logging.DEBUG) #下面指定了handler的信息输出格式，其中asctime,name,levelname，message都是logging的关键字formatter=logging.Formatter(‘%(asctime)s - %(name)s - %(levelname)s - %(message)s‘)fh.setFormatter(formatter)sh.setFormatter(formatter) #把Handler加入到logger中，可理解为给处理者在logger中安排了职位logger.addHandler(fh)logger.addHandler(sh) #记录一条为”Hello,Arsenal!”的info日志信息logger.info(‘Hello,Arsenal!‘)print("process end！")

Attention:

Logger.setlevel (LVL)
The level of the logger is set to the following levels:
NOTSET < DEBUG < INFO < WARNING < ERROR < CRITICAL
If the Looger level is set to info, then logs less than the info level are not output, and logs that are greater than or equal to the info level are output

Study Questions

Run the following log system to find errors and correct them.

?

1234567891011121314151617181920

importlogging  logger=logging.getLogger(‘lylogger‘)logger.setLevel(logging.DEBUG) fh=logging.FileHandler(‘test.log‘)fh.setLevel(logging.DEBUG) sh=logging.StreamHandler()sh.setLevel(logging.DEBUG) formatter=logging.Formatter(‘%(asctime)s - %(name)s - %(levlename)s - %(message)s‘)fh.setFormatter(formatter)sh.setFormatter(formatter) logger.addHandler(fh)logger.addHandler(sh)  logger.info(‘Hello,Arsenal!‘)print("process end！")

Answer:

By looking at the error message, locate the Key:levlename, and learn that the keyword LevelName is incorrectly written.

How to use Python's logging module