logging的使用

A simple example

• the default log of level is WARNING

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  import logging logging.warning('Watch out!') logging.info('I told you so') # will not print anything

1	WARNING:root:Watch out!

Logging to a file

主要说明如何将日志打印到文件中,以及如何刷新日志(不保留原有的日志).

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import logging # set filename and log level logging.basicConfig(filename='example.log',level=logging.DEBUG) # If you want each run to start afresh, not remembering the messages from earlier runs, you can specify the filemode argument, # logging.basicConfig(filename='example.log', filemode='w', level=logging.DEBUG) logging.debug('This message should go to the log file') logging.info('So should this') logging.warning('And this, too')

Logging variable data

主要说明日志输出是可以使用变量的

1 2	import logging logging.warning('%s before you %s', 'Look', 'leap!')

Changing the format of displayed messages

主要说明如何改变日志输出格式以及是时间输出格式如何改变

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import logging # you can use 'format=' to formulate what you want output logging.basicConfig(format='%(levelname)s:%(message)s', level=logging.DEBUG) logging.debug('This message should appear on the console') logging.info('So should this') logging.warning('And this, too') # detefmt can formulate format of date logging.basicConfig(format='%(asctime)s %(message)s', datefmt='%m/%d/%Y %I:%M:%S %p') logging.warning('is when this event was logged.')

Configuring Logging

主要说明日志如何新建日志的实例对象以及如何配置日志文件

建立日志对象

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import logging # create logger logger = logging.getLogger('simple_example') logger.setLevel(logging.DEBUG) # create console handler and set level to debug ch = logging.StreamHandler() ch.setLevel(logging.DEBUG) # create formatter formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s') # add formatter to ch ch.setFormatter(formatter) # add ch to logger logger.addHandler(ch) # 'application' code logger.debug('debug message') logger.info('info message') logger.warn('warn message') logger.error('error message') logger.critical('critical message')

建立日志对象并且读取日志配置文件

1 2 大专栏  logging的使用ass="line">3 4 5 6 7 8 9 10 11 12 13 14

import logging import logging.config logging.config.fileConfig('logging.conf') # create logger logger = logging.getLogger('simpleExample') # 'application' code logger.debug('debug message') logger.info('info message') logger.warn('warn message') logger.error('error message') logger.critical('critical message')

logging.conf

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[loggers] keys=root,simpleExample [handlers] keys=consoleHandler [formatters] keys=simpleFormatter [logger_root] level=DEBUG handlers=consoleHandler [logger_simpleExample] level=DEBUG handlers=consoleHandler qualname=simpleExample propagate=0 [handler_consoleHandler] class=StreamHandler level=DEBUG formatter=simpleFormatter args=(sys.stdout,) [formatter_simpleFormatter] format=%(asctime)s - %(name)s - %(levelname)s - %(message)s datefmt=

another logging.conf

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[loggers] keys=root,simple [handlers] keys=consoleHandler,fileHandler,rotatingFileHandler [formatters] keys=simpleFmt [logger_root] level=DEBUG handlers=consoleHandler # handlers=fileHandler # handlers=rotatingFileHandler [logger_simple] level=DEBUG handlers=consoleHandler,fileHandler qualname=simple propagate=0 [handler_consoleHandler] class=StreamHandler level=DEBUG formatter=simpleFmt args=(sys.stdout,) [handler_fileHandler] class=FileHandler level=DEBUG formatter=simpleFmt args=('test.log', 'w') [handler_rotatingFileHandler] class=handlers.RotatingFileHandler level=DEBUG formatter=simpleFmt args=("python.log", "a", 20*1024*1024, 10) [formatter_simpleFmt] format=%(asctime)s - %(name)s - %(levelname)s - %(message)s - [%(filename)s:%(lineno)s] datefmt=

Level	Numeric value
CRITICAL	50
ERROR	40
WARNING	30
INFO	20
DEBUG	10
NOTSET	0

Format	Description
%(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