python - logging
by 宋强
直接使用类似
logging.warning('Watch out!')
就可以输出，总共有几种，描述如下：
| gate | |
|---|---|
| logging.info() | 调试信息 |
| logging.debug() | 调试信息 |
| logging.warn() | log程序应该能解决的警告 |
| logging.warning | log程序无法解决的警告 |
| logging.error() | 错误 |
| logging.exception() | 异常 |
| logging.critical() | 非常严重，系统停止 |
logging模块存在一个默认等级，INFO、DEBUG、WARNING、ERROR、CRITICAL，只有在这个等级和比这个等级高的错误会输出，默认是WARNING，
增加修改方式。
输出到文件
import logging
logging.basicConfig(filename='example.log',level=logging.DEBUG)
logging.debug('This message should go to the log file')
logging.info('So should this')
logging.warning('And this, too')
覆盖log可以增加打开模式信息
logging.basicConfig(filename='example.log', filemode='w', level=logging.DEBUG)
logging支持格式化输出
logging.warning('%s before you %s', 'Look', 'leap!')
想要更改整个输出信息的格式的话，可以使用：
logging.basicConfig(format='%(levelname)s:%(message)s', level=logging.DEBUG)
输出形如：
DEBUG:This message should appear on the console
INFO:So should this
WARNING:And this, too
增加时间段：
logging.basicConfig(format='%(asctime)s %(message)s', datefmt='%m/%d/%Y %I:%M:%S %p')
logging.warning('is when this event was logged.')
输出形如：
12/12/2010 11:46:36 AM is when this event was logged.
可以不指定datefmt。
可以格式化的选项：
- name – The name of the logger used to log the event represented by this LogRecord. Note that this name will always have this value, even though it may be emitted by a handler attached to a different (ancestor) logger.
- level – The numeric level of the logging event (one of DEBUG, INFO etc.) Note that this is converted to two attributes of the LogRecord: levelno for the numeric value and levelname for the corresponding level name.
- pathname – The full pathname of the source file where the logging call was made.
- lineno – The line number in the source file where the logging call was made.
- msg – The event description message, possibly a format string with placeholders for variable data.
- args – Variable data to merge into the msg argument to obtain the event description.
- exc_info – An exception tuple with the current exception information, or None if no exception information is available.
- func – The name of the function or method from which the logging call was invoked.
- sinfo – A text string representing stack information from the base of the stack in the current thread, up to the logging call.