python连接linux获取日志_Python记录日志的方法

日志不管对于开发或者运维都是一项非常重要的东西，它可以用来排错，解决故障，统计分析等。

本文介绍python中的日志库的用法。

导入日志库：import logging

日志库的主要有以下方法：获取日志名,比如

logging.getLogger(__name__)

定义Handler,比如

logging.FileHandler('/var/log/messages')

设置级别，比如

fh.setLevel(logging.DEBUG)

定义格式，比如

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

打印日志，比如

LOG.error("python logging test!!")

实例1

下面给出一段脚本用来输出日志到/var/log/messages和屏幕。import logging

LOG = logging.getLogger(__name__)

LOG.setLevel(logging.ERROR)

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

fh = logging.FileHandler('/var/log/messages')

fh.setLevel(logging.DEBUG)

fh.setFormatter(formatter)

LOG.addHandler(fh)

ch = logging.StreamHandler()

ch.setLevel(logging.ERROR)

ch.setFormatter(formatter)

LOG.addHandler(ch)

LOG.error("python logging test!!")

运行下，你会发现/var/log/messages和屏幕上都会有类似“2015-06-28 07:41:41,527 - test - ERROR - python logging test!!”。

实例2

如果只是记录日志到一个文件或屏幕，可以采用简单的方法：logging.basicConfig()

import logging

logging.basicConfig(filename='example.log', level=logging.DEBUG)

logging.error("this is a error test")

实例3

下面介绍需要记录日志到不同文件的方法，这时就不能采用logging.basicConfig()了。

有两个文件，一个是main.py,一个是logger.py ，

输出到不同的日志文件需要获取不同的日志对象:logging.getLogger()

cat main.py

#!/usr/bin/env python

import logging

from logger import logger

list = ['test1', 'test2']

msg1 = "This is a testing !"

msg2 = "This is the second testing !"

def set_logger(logger_name, log_file, level=logging.INFO):

#logging.basicConfig(filename=name, level=logging.DEBUG, format='%(asctime)s %(name)s %(message)s')

l = logging.getLogger(logger_name)

formatter = logging.Formatter('%(asctime)s : %(message)s')

fileHandler = logging.FileHandler(log_file, mode='w')

fileHandler.setFormatter(formatter)

#streamHandler = logging.StreamHandler()

#streamHandler.setFormatter(formatter)

l.setLevel(level)

l.addHandler(fileHandler)

#l.addHandler(streamHandler)

for logger_name in list:

log_file = logger_name

set_logger(logger_name, log_file, level=logging.INFO)

logger(logger_name, msg1)

logger(logger_name, msg2)

cat logger.py

#!/usr/bin/env python

import logging

import os

import getpass

def log_flock(runner):

if runner is not None:

try:

fcntl.lockf(runner.output_lockfile, fcntl.LOCK_EX)

except OSError:

# already got closed?

pass

else:

pass

def log_unflock(runner):

if runner is not None:

try:

fcntl.lockf(runner.output_lockfile, fcntl.LOCK_UN)

except OSError:

# already got closed?

pass

else:

pass

def logger(logger_name, msg, flag=None, runner=None):

log_flock(runner)

mypid = str(os.getpid())

user = getpass.getuser()

log = logging.getLogger(logger_name)

if flag == 'red':

log.error(msg)

else:

log.info(msg)

log_unflock(runner)