Python学习系列之logging模块

实例一:日志写进一个文件

代码:

import logging

logging.basicConfig(level=logging.DEBUG,
format='%(asctime)s  %(filename)s [line:%(lineno)d] %(levelname)s  %(message)s', #定义日志格式
datefmt='%Y-%m-%d %H:%M:%S %p', #定义asctime
filename='test.log',            #定义日志文件
filemode='a')                   #定义写入模式,'a'是追加的意思



 login():
    while True:
        try:
            name = input('Input user name:')
            password = int(input('Input password:'))   #这里故意转成整型，触发异常
            if name == 'andy' and password == 'nopasswd':
                print('logging succeed!')
        except ValueError as e:
            logging.info(e)      #这里写入日志
            break

if __name__ == '__main__':
    login()

format解释:

asctime:时间,按照datefmt定义的显示,2018-01-10 14:50:25
filename:报错的python文件名称
line:%(lineno)d:报错的行数
levelname:报错级别
message:报错的信息

测试:

[root@admin_bak shell]# python3.6  test_log.py
Input user name:asdasd
Input password:asdsad  #这是输入字符串,触发异常

查看日志

2018-01-10 11:54:40 AM test_log.py test_log.py[line:21] DEBUG invalid literal for int() with base 10: 'asdsad'

实例二:实现每天一个日志文件

代码:

import time

import logging
import logging.handlers

LOG_FILE = "ping.log"          #设置日志文件名称
logger = logging.getLogger()   #实例化logging
logger.setLevel(logging.INFO)  #设置日志级别


#添加TimedRotatingFileHandler  
#定义一秒换一次log文件的handlers
#保留3个旧log文件
fh = logging.handlers.TimedRotatingFileHandler(LOG_FILE, when='D', interval=1, backupCount=10)
#定义asctime
datefmt = '%Y-%m-%d %H:%M:%S'
#定义日志格式
format_str = '%(asctime)s %(filename)s [line:%(lineno)d] %(levelname)s %(message)s'
formatter = logging.Formatter(format_str, datefmt)
fh.setFormatter(formatter)
logger.addHandler(fh)


while True:
    time.sleep(0.1)
    logging.info("test")

TimedRotatingFileHandler

TimedRotatingFileHandler(filename [,when [,interval [,backupCount]]])#需要传的参数

filename:日志文件

when:

"S":second

"M":minutes

"H":Hours

"D":Days

"W":week day (0=monday)

interval:是指等待多少个"when"时间后,logging会自动新建文件,比如when='S',interval=10,就是10个一秒后新建文件,也就是10秒,when='D',interval=1,就是一天一个文件

backupCount:保留日志文件的个数　　