python logging 模块

日志级别：
Number Name
50 CRITICAL
40 ERROR
30 WARNING(默认)
20 INFO
10 DEBUG
**比设定的level低的level会被过滤掉，不打印

输出格式：
%(name)s 日志名称
%(asctime)s 日志时间
%(filename)s 文件名
%(pathname)s 文件的全路径名
%(funcName)s 函数名
%(levelname)s 日志等级
%(levelno)s 数字化日志等级
%(lineno)d 行数
%(module)s 模块名
%(msecs)d 时间中毫秒部分
%(process)d 进程ID
%(processName)s 进程名
%(thread)d 线程ID
%(threadName)s 线程名

一.基础basicConfig用法
import logging
logging.basicConfig(level = logging.INFO,format = '%(asctime)s - %(name)s - %(levelname)s - %(message)s')
logger=logging.getLogger(__file__) #如果不给定参数，默认参数为root

logger.info('this is a info message')
logger.debug('this is a debug message')
logger.error('this is a error message')

*补充*
basicConfig的参数:
level:设置日志级别
format:指定输出格式，如上面的输出格式
filename:创建FileHandler，当这个参数使用后，不再使用StreamHandler
filemode:文件写入方式，默认是a
datefmt:设定时间日期格式，这个格式会覆盖format里面的asctime的格式
stream:设定StreamHandler,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参数同时指定时，stream会被忽略

二.FileHandler,StreamHandler日志输出到屏幕和console

import logging
import time

#create logger
logger=logging.getLogger(__file__)
logger.setLevel(logging.DEBUG)

#create FileHandler
filehandler=logging.FileHandler('a.log')
filehandler.setLevel(logging.INFO)

#create StreamFilehandler
streamhandler=logging.StreamHandler()
streamhandler.setLevel(logging.INFO)

#Create formatter
formatter=logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')
formatter.datefmt="%Y-%m-%d %H:%M:%S"

filehandler.setFormatter(formatter)
streamhandler.setFormatter(formatter)

logger.addHandler(filehandler)
logger.addHandler(streamhandler)


logger.info('this is a info message')
logger.debug('this is a debug message')
logger.error('this is a error message')

三.Config.ini文件来配置logging模块：

Config.ini文件：

######################Formatters###################
[formatters]
keys=f1			#定义f1 formatter，可以定义多个，key=f1,f2,f3...

[formatter_f1]		#注意格式是formatter_f1
format=%(filename)s-%(levelname)s-%(message)s
datefmt=%Y-%m-%d %H:%M:%S


#####################Handlers######################
[handlers]
keys=h1,h2		#定义h1,h2两个handler，一个是FileHandler,一个是StreamHandler

[handler_h1]		#注意格式handler_h1
class=FileHandler
args=('a.log','a')	
level=INFO
formatter=f1

[handler_h2]		#注意格式handler_h2
class=StreamHandler
args=(sys.stdout,)	#注意sys.stdout后面的，号	
level=INFO
formatter=f1


###################loggers#######################
[loggers]
keys=root	#root是父类，是必须的，还可以自定义其它的，key=root,l1,l2...

[logger_root]	#注意格式
level=DEBUG
handlers=h1,h2	#同时输出到console和文件

import logging
from logging.config import fileConfig

fileConfig('logger_config.ini')
logger1=logging.getLogger()
logger1.info('this is a info message')

四.yaml 文件配置logging模块

logger.yaml:

version: 1
disable_existing_logger: False

formatters:
    f1:
        format: "%(filename)s-%(levelname)s-%(message)s"
        datefmt: "%Y-%m-%d %H:%M:%S"


handlers:
    h1:
        class: logging.StreamHandler
        level: INFO
        formatter: f1
        stream: ext://sys.stdout

    h2:
        class: logging.FileHandler
        level: INFO
        formatter: f1
        filename: 'a.log'



loggers:
    l1:
        level: DEBUG
        handlers: [h1,h2]
        propagate: no

root:
    level: INFO
    handlers: [h1,h2]

import logging
import yaml
from logging.config import dictConfig

with open('logger.yaml','r') as f:
    config=yaml.safe_load(f)

dictConfig(config)

logger=logging.getLogger()
logger.info('this is a info message')

五.json文件配置logging模块

logger.json:

{
  "version": 1,
  "disable_existing_loggers": false,

  "formatters":{
    "f1":{
      "format": "%(asctime)s - %(name)s - %(levelname)s - %(message)s",
      "datefmt": "%Y-%m-%d %H:%M:%S"
    }
  },

  "handlers": {
    "h1": {
      "class": "logging.FileHandler",
      "level": "INFO",
      "formatter": "f1",
      "filename": "a.log"
    },
    "h2": {
      "class": "logging.StreamHandler",
      "level": "INFO",
      "formatter": "f1",
      "stream": "ext://sys.stdout"
    }
  },

  "loggers":{
    "l1":{
      "level": "DEBUG",
      "handlers": [
        "h1",
        "h2"
      ]
    }
  },

  "root":{
    "level":"DEBUG",
    "handlers":["h1","h2"]
  }

}

import logging
import json
from logging.config import dictConfig

with open('logger.json','r') as f:
    config=json.load(f)

dictConfig(config)
logger=logging.getLogger()
logger.info('this is a info message')