Python:通过具有多个Excepts的Try/Except块传播异常

Question

有没有办法将try/except块中的异常从一个传播到另一个除外？

我想捕获一个特定的错误,然后进行一般的错误处理.

"raise"允许异常"冒泡"到外部try/except,但不在try/except块内引发错误.

理想情况应该是这样的:

import logging

def getList():
    try:
        newList = ["just", "some", "place", "holders"]
        # Maybe from something like: newList = untrustedGetList()

        # Faulty List now throws IndexError
        someitem = newList[100]

        return newList

    except IndexError:
        # For debugging purposes the content of newList should get logged.
        logging.error("IndexError occured with newList containing: \n%s",   str(newList))

    except:
        # General errors should be handled and include the IndexError as well!
        logging.error("A general error occured, substituting newList with backup")
        newList = ["We", "can", "work", "with", "this", "backup"]
        return newList

我遇到的问题是当IndexError被第一个捕获时除外,我的常规错误处理在第二个除了块之外没有应用.

我现在唯一的解决方法是在第一个块中包含一般错误处理代码.即使我将它包装在它自己的功能块中,它仍然看起来不那么优雅......

Answer 1

您有两个选择：

• 不要IndexError使用专用except ..块。您始终可以通过捕获BaseException异常并将其分配给名称（此处e）来手动测试常规块中的异常类型：

  try:
      # ...
  except BaseException as e:
      if isinstance(e, IndexError):
          logging.error("IndexError occured with newList containing: \n%s",   str(newList))
  
      logging.error("A general error occured, substituting newList with backup")
      newList = ["We", "can", "work", "with", "this", "backup"]
      return newList
  

• 使用嵌套try..except语句并重新提出：

  try:
      try:
          # ...
      except IndexError:
          logging.error("IndexError occured with newList containing: \n%s",   str(newList))
          raise
  except:
      logging.error("A general error occured, substituting newList with backup")
      newList = ["We", "can", "work", "with", "this", "backup"]
      return newList