我试图在我的Python 2.7应用程序中实现日志记录,并发现它非常有用.但是,我注意到,当以交互方式运行Python时,每个日志消息都会打印多次.打印消息的次数与我之前运行脚本的次数相同,因此在脚本结束时似乎没有正确清理记录器(我猜).请考虑以下示例:
import sys
import logging
def main(argv=None):
log = logging.getLogger('test')
log.setLevel(logging.DEBUG)
console_handler = logging.StreamHandler()
console_handler.setFormatter(logging.Formatter("%(message)s"))
log.addHandler(console_handler)
log.info('Starting something...')
log.info('Doing something...')
log.info('Finished something.')
logging.shutdown()
if __name__=='__main__':
sys.exit(main(sys.argv[1:]))
打字
>>> import file.py
>>> file.main()
产生以下结果:
Starting something...
Doing something...
Finished something.
然后第二次输入file.main()会产生:
Starting something...
Starting something...
Doing something...
Doing something...
Finished something.
Finished something.
重复第三次会给出三条或每条消息,依此类推.有谁知道为什么会这样 – 这是日志记录模块的预期行为,如果是这样,我该如何更改?如果按预期运行脚本(python file.py),上面的脚本只打印每条消息中的一条.
解决方法:
是的,您正在创建和重用记录器的单个实例.添加到该记录器的每个处理程序也记录一条消息.
您可能希望日志记录设置位于模块级别或单独的函数中,因此您只需运行一次.
也许是这样的:
import atexit
import sys
import logging
log = logging.getLogger('test')
log.setLevel(logging.DEBUG)
console_handler = logging.StreamHandler()
console_handler.setFormatter(logging.Formatter("%(message)s"))
log.addHandler(console_handler)
def shutdown_logging():
logging.shutdown()
atexit.register(shutdown_logging)
def main(argv=None):
log.info('Starting something...')
log.info('Doing something...')
log.info('Finished something.')
if __name__=='__main__':
sys.exit(main(sys.argv[1:]))