logging模块
顾名思义,用于程序日志输出,可以设置日志级别、格式、输出方式等,基本使用方法如下:
1、logging.basicConfig方式
简单的配置,只能选择单独输出到屏幕或输出到文件,不能同时输出。例如:
#-*- coding:utf-8 -*-
#只能选择输出到屏幕或文件
import logging
logging.basicConfig(level=logging.DEBUG,
format='%(asctime)s %(filename)s[line:%(lineno)d] %(levelname)s %(message)s',
datefmt='%a,%d %b %Y %H:%M:%S',
filename='test.log',
filemode='a')
'''
参数:
level:指定输出的日志级别
format:指定日志格式,包括:
asctime:时间
filename:日志归属的文件名称
lineno:日志对应代码在归属文件中的行号
levelname:日至最低级别,不指定默认为warning
message:具体的日志内容,
datefmt:指定具体的时间格式,如果不指定,asctime将使用默认格式,如:2018-05-05 22:07:30,578
filename:指定日志文件名称,可携带具体路径,不指定该参数时日志输出到屏幕
filemode:指定日志写入模式,默认为'a'表示追加,可以指定为'w'表示覆盖
'''
logging.debug('debug message')
logging.info('info message')
logging.warning('warning message')
logging.error('error message')
logging.critical('critical message')
上面例子将日志输出到test.log文件,内容:
Sat,05 May 2018 22:25:14 2.py[line:22] DEBUG debug message
Sat,05 May 2018 22:25:14 2.py[line:23] INFO info message
Sat,05 May 2018 22:25:14 2.py[line:24] WARNING warning message
Sat,05 May 2018 22:25:14 2.py[line:25] ERROR error message
Sat,05 May 2018 22:25:14 2.py[line:26] CRITICAL critical message
如果,只需要日志输出到屏幕,只需要将filename='test.log'和filemode='a'两行注释掉即可。
2、logging.getLogger方式
完整配置,即可单独输出到屏幕或文件,也可同时输出。例如:
#-*- coding:utf-8 -*-
#日志输出更灵活,可以分别或同时输出到屏幕和文件
import logging
#创建一个logger对象
logger=logging.getLogger()
#创建一个文件输出流handler,用于写入日志文件
fm=logging.FileHandler('test1.log')
#再创建一个标准输出流handler,用于输出到屏幕
pm=logging.StreamHandler()
#创建一个日志格式对象
formatter=logging.Formatter('%(asctime)s %(filename)s[line:%(lineno)d] %(levelname)s %(message)s')
#为两个handler添加日志格式
fm.setFormatter(formatter)
pm.setFormatter(formatter)
#为logger对象添加handler
logger.addHandler(fm)
logger.addHandler(pm)
#设置输出日志级别,默认只输出warning以上
logger.setLevel(logging.DEBUG)
logger.debug('debug message')
logger.info('info message')
logger.warning('warning message')
logger.error('error message')
logger.critical('critical message')
上面例子,将日志同时输出到屏幕和test1.log文件,内容:
2018-05-05 22:32:52,800 3.py[line:28] DEBUG debug message
2018-05-05 22:32:52,800 3.py[line:29] INFO info message
2018-05-05 22:32:52,800 3.py[line:30] WARNING warning message
2018-05-05 22:32:52,800 3.py[line:31] ERROR error message
2018-05-05 22:32:52,800 3.py[line:32] CRITICAL critical message
logger.addHandler()决定日志输出方向,如果只输出到某一方面,可以将另一行注释掉。
3、具体应用
#!/usr/local/python-3.4/bin/python3.4
#-*- coding:utf-8 -*-
import urllib.request
import time
import logging
#这里用于请求某个url,并返回状态码
my_url='http://172.16.1.20:8080/bizmon/BIZServlet?BizCode=DX0001&BatchId=%s' %(int(time.time()))
def url_request():
url_response=urllib.request.urlopen(my_url)
url_code=url_response.code
return url_code
#定义自己的日志函数
def get_log():
logger=logging.getLogger()
fh=logging.FileHandler('test.log')
ph=logging.StreamHandler()
formatter=logging.Formatter('%(asctime)s %(filename)s[line:%(lineno)d] %(levelname)s %(message)s')
fh.setFormatter(formatter)
logger.addHandler(fh)
# logger.addHandler(ph)
logger.setLevel(logging.INFO)
return logger
if __name__ == "__main__":
my_log=get_log()
try:
code=url_request()
except Exception:
my_log.error("%s request failed!"%(my_url),exc_info=True) #捕获异常,输出到日志中
else:
my_log.info("%s request successful! code is %s"%(my_url,code)) #正常日志
日志内容:
2018-05-07 19:41:41,575 16.py[line:28] ERROR http://172.16.1.20:8080/bizmon/BIZServlet?BizCode=DX0001&BatchId=1525693301 request failed!
Traceback (most recent call last):
File "C:/Users/Administrator/PycharmProjects/first/16.py", line 26, in <module>
code=url_request()
File "C:/Users/Administrator/PycharmProjects/first/16.py", line 8, in url_request
url_response=urllib.request.urlopen(my_url)
File "C:\Python3.6\lib\urllib\request.py", line 223, in urlopen
return opener.open(url, data, timeout)
File "C:\Python3.6\lib\urllib\request.py", line 532, in open
response = meth(req, response)
File "C:\Python3.6\lib\urllib\request.py", line 642, in http_response
'http', request, response, code, msg, hdrs)
File "C:\Python3.6\lib\urllib\request.py", line 570, in error
return self._call_chain(*args)
File "C:\Python3.6\lib\urllib\request.py", line 504, in _call_chain
result = func(*args)
File "C:\Python3.6\lib\urllib\request.py", line 650, in http_error_default
raise HTTPError(req.full_url, code, msg, hdrs, fp)
urllib.error.HTTPError: HTTP Error 500: Internal Server Error
在捕获异常时,
my_log.error("%s request failed!"%(my_url),exc_info=True)也可写成:my_log.exception("%s request failed!"%(my_url))