Python記錄日誌的方法
- 2020 年 1 月 7 日
- 筆記
日誌不管對於開發或者運維都是一項非常重要的東西，它可以用來排錯，解決故障，統計分析等。
本文介紹python中的日誌庫的用法。
導入日誌庫：import logging
日誌庫的主要有以下方法：
- 獲取日誌名,比如 logging.getLogger（__name__）
- 定義Handler,比如 logging.FileHandler('/var/log/messages')
- 設置級別，比如 fh.setLevel(logging.DEBUG)
- 定義格式，比如 formatter = logging.Formatter('%(asctime)s – %(name)s – %(levelname)s – %(message)s')
- 列印日誌，比如 LOG.error("python logging test!!")
實例1
下面給出一段腳本用來輸出日誌到/var/log/messages和螢幕。
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!!")
運行下，你會發現/var/log/messages和螢幕上都會有類似「2015-06-28 07:41:41,527 – test – ERROR – python logging test!!」。
實例2
如果只是記錄日誌到一個文件或螢幕，可以採用簡單的方法：logging.basicConfig()
import logging
logging.basicConfig(filename='example.log', level=logging.DEBUG)
logging.error("this is a error test")
實例3
下面介紹需要記錄日誌到不同文件的方法，這時就不能採用logging.basicConfig()了。
有兩個文件，一個是main.py,一個是logger.py ，
輸出到不同的日誌文件需要獲取不同的日誌對象: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)
