异常必须派生自BaseException [英] Exceptions must derive from BaseException

问题描述

我在这里想念什么?

import sys

class MyBaseError(BaseException):
    def __init__(self, message, base_message=None, *args):
        
        self.message = message
        self.base_message = base_message
        super(MyBaseError, self).__init__()
        
        
    def __str__(self):
        if self.base_message is None:
            return self.message
        
        return self.message + " '" + str(self.base_message) + "'"
        
        
class MyError(MyBaseError):
    """
    """
    
class MyTypeError(MyError):
    """
    """

def run_me():
    raise MyTypeError("run_me")
    

def sayonara():
    try:
        run_me()
    except (MyBaseError) as e:
        raise(MyBaseError("unable to run",
                           e,
                           e.args),
                sys.exc_info()[2])
        
sayonara()

错误:

Traceback (most recent call last):
  File "main.py", line 32, in sayonara
    run_me()
  File "main.py", line 27, in run_me
    raise MyTypeError("run_me")
__main__.MyTypeError: run_me

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "main.py", line 42, in <module>
    sayonara()
  File "main.py", line 40, in sayonara
    sys.exc_info()[2])
TypeError: exceptions must derive from BaseException

MyBaseError类已经从BaseException派生了.

MyBaseError class is already deriving from BaseException.

推荐答案

在您的sayonara()函数中，您似乎正在尝试引发异常的元组.问题在于sys.exc_info()[2]是一个追溯，而不是一个例外，这是造成中断的原因.我通过将以下行放在异常块的顶部来验证了这一点:

In your sayonara() function, it seems you are attempting to raise a tuple of exceptions. The problem is that sys.exc_info()[2] is a traceback, and not an exception, which is the cause of your break. I verified this by placing the following line at the top of the exception block:

print(type(sys.exc_info()[2]))

我不确定您要做什么，但是sayonara()的有效版本如下:

I'm not certain of what you are trying to do for sure, but a working version of sayonara() is as follows:

def sayonara():
try:
    run_me()
except (MyBaseError) as e:
    raise MyBaseError("unable to run", e, e.args)

如果要包括回溯，则需要更新自定义的Error类以处理传递的自变量.

If you want to include the traceback, you'll need to update your custom Error classes to handle that argument being passed through.

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