python(36):python日志打印,保存,logging模块学习

时间:2022-06-12 12:05:14

1.简单的将日志打印到屏幕

import logging

logging.debug('This is debug message')
logging.info('This is info message')
logging.warning('This is warning message') 屏幕上打印:
WARNING:root:This is warning message

默认情况下,logging将日志打印到屏幕,日志级别为WARNING;
日志级别大小关系为:CRITICAL > ERROR > WARNING > INFO > DEBUG > NOTSET,当然也可以自己定义日志级别。

2.通过logging.basicConfig函数对日志的输出格式及方式做相关配置

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='myapp.log',
filemode='w') logging.debug('This is debug message')
logging.info('This is info message')
logging.warning('This is warning message') ./myapp.log文件中内容为:
Sun, May :: demo2.py[line:] DEBUG This is debug message
Sun, May :: demo2.py[line:] INFO This is info message
Sun, May :: demo2.py[line:] WARNING This is warning message

logging.basicConfig函数各参数:
filename: 指定日志文件名
filemode: 和file函数意义相同,指定日志文件的打开模式,'w'或'a'
format: 指定输出的格式和内容,format可以输出很多有用信息,如上例所示:
 %(levelno)s: 打印日志级别的数值
 %(levelname)s: 打印日志级别名称
 %(pathname)s: 打印当前执行程序的路径,其实就是sys.argv[0]
 %(filename)s: 打印当前执行程序名
 %(funcName)s: 打印日志的当前函数
 %(lineno)d: 打印日志的当前行号
 %(asctime)s: 打印日志的时间
 %(thread)d: 打印线程ID
 %(threadName)s: 打印线程名称
 %(process)d: 打印进程ID
 %(message)s: 打印日志信息
datefmt: 指定时间格式,同time.strftime()
level: 设置日志级别,默认为logging.WARNING
stream: 指定将日志的输出流,可以指定输出到sys.stderr,sys.stdout或者文件,默认输出到sys.stderr,当stream和filename同时指定时,stream被忽略

3.将日志同时输出到文件和屏幕

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='myapp.log',
filemode='w') #################################################################################################
#定义一个StreamHandler,将INFO级别或更高的日志信息打印到标准错误,并将其添加到当前的日志处理对象#
console = logging.StreamHandler()
console.setLevel(logging.INFO)
formatter = logging.Formatter('%(name)-12s: %(levelname)-8s %(message)s')
console.setFormatter(formatter)
logging.getLogger('').addHandler(console)
################################################################################################# logging.debug('This is debug message')
logging.info('This is info message')
logging.warning('This is warning message') 屏幕上打印:
root : INFO This is info message
root : WARNING This is warning message ./myapp.log文件中内容为:
Sun, May :: demo2.py[line:] DEBUG This is debug message
Sun, May :: demo2.py[line:] INFO This is info message
Sun, May :: demo2.py[line:] WARNING This is warning message

4.logging之日志回滚

import logging
from logging.handlers import RotatingFileHandler #################################################################################################
#定义一个RotatingFileHandler,最多备份5个日志文件,每个日志文件最大10M
Rthandler = RotatingFileHandler('myapp.log', maxBytes=**,backupCount=)
Rthandler.setLevel(logging.INFO)
formatter = logging.Formatter('%(name)-12s: %(levelname)-8s %(message)s')
Rthandler.setFormatter(formatter)
logging.getLogger('').addHandler(Rthandler)
################################################################################################

从上例和本例可以看出,logging有一个日志处理的主对象,其它处理方式都是通过addHandler添加进去的。
logging的几种handle方式如下:

logging.StreamHandler: 日志输出到流,可以是sys.stderr、sys.stdout或者文件
logging.FileHandler: 日志输出到文件 日志回滚方式,实际使用时用RotatingFileHandler和TimedRotatingFileHandler
logging.handlers.BaseRotatingHandler
logging.handlers.RotatingFileHandler
logging.handlers.TimedRotatingFileHandler logging.handlers.SocketHandler: 远程输出日志到TCP/IP sockets
logging.handlers.DatagramHandler: 远程输出日志到UDP sockets
logging.handlers.SMTPHandler: 远程输出日志到邮件地址
logging.handlers.SysLogHandler: 日志输出到syslog
logging.handlers.NTEventLogHandler: 远程输出日志到Windows NT//XP的事件日志
logging.handlers.MemoryHandler: 日志输出到内存中的制定buffer
logging.handlers.HTTPHandler: 通过"GET"或"POST"远程输出到HTTP服务器

由于StreamHandler和FileHandler是常用的日志处理方式,所以直接包含在logging模块中,而其他方式则包含在logging.handlers模块中,
上述其它处理方式的使用请参见python2.5手册!

5.通过logging.config模块配置日志

#logger.conf

###############################################

[loggers]
keys=root,example01,example02 [logger_root]
level=DEBUG
handlers=hand01,hand02 [logger_example01]
handlers=hand01,hand02
qualname=example01
propagate= [logger_example02]
handlers=hand01,hand03
qualname=example02
propagate= ############################################### [handlers]
keys=hand01,hand02,hand03 [handler_hand01]
class=StreamHandler
level=INFO
formatter=form02
args=(sys.stderr,) [handler_hand02]
class=FileHandler
level=DEBUG
formatter=form01
args=('myapp.log', 'a') [handler_hand03]
class=handlers.RotatingFileHandler
level=INFO
formatter=form02
args=('myapp.log', 'a', **, ) ############################################### [formatters]
keys=form01,form02 [formatter_form01]
format=%(asctime)s %(filename)s[line:%(lineno)d] %(levelname)s %(message)s
datefmt=%a, %d %b %Y %H:%M:%S [formatter_form02]
format=%(name)-12s: %(levelname)-8s %(message)s
datefmt=

上例3:

import logging
import logging.config logging.config.fileConfig("logger.conf")
logger = logging.getLogger("example01") logger.debug('This is debug message')
logger.info('This is info message')
logger.warning('This is warning message')

上例4:

import logging
import logging.config logging.config.fileConfig("logger.conf")
logger = logging.getLogger("example02") logger.debug('This is debug message')
logger.info('This is info message')
logger.warning('This is warning message')

6.logging是线程安全的

使用案例:

import logging
FORMAT = '[%(asctime)s, %(levelname)-7s]: %(message)s'
logging.basicConfig(format=FORMAT)
logger = logging.getLogger('spider')
logger.setLevel(logging.INFO)
logger.info('start get the audio url') #------------print-------------- [2017-05-22 16:13:09,607, INFO ]: start get the audio url

7.logging是线程安全的

from:http://blog.csdn.net/yatere/article/details/6655445