Question

我可能在这里错误地表达了这个问题，但我刚刚观察到了python的日志记录模块的奇怪行为。以下代码段不起作用，至少在OSX

上

import logging
import sys


root = logging.getLogger()
root.addHandler(
     logging.StreamHandler(stream=sys.stdout).setFormatter(
             logging.Formatter('%(asctime)s - %(levelname)s - %(message)s')
      ))
root.setLevel(logging.INFO)
root.info('initializing ...')

以上代码产生此异常

    root.info('initializing ...')
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/logging/__init__.py", line 1165, in info
self._log(INFO, msg, args, **kwargs)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/logging/__init__.py", line 1284, in _log
self.handle(record)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/logging/__init__.py", line 1294, in handle
self.callHandlers(record)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/logging/__init__.py", line 1333, in callHandlers
  if record.levelno >= hdlr.level:
AttributeError: 'NoneType' object has no attribute 'level'

另一方面，类似的代码片段完全正常。

import logging
import sys

root = logging.getLogger()
handler = logging.StreamHandler(stream=sys.stdout)
formatter = logging.Formatter(
    fmt='%(asctime)s - %(levelname)s - %(message)s')
handler.setFormatter(formatter)
root.addHandler(handler)
root.setLevel(logging.INFO)

root.info('initializing...')

第二个代码段的作用是什么？

日志记录：如果处理程序未提前启动，则设置处理程序不起作用

0 个答案: