[Python-Dev] Revert #12085 fix for __del__ attribute error message

[Terry Reedy]

On 9/22/2013 2:41 PM, Guido van Rossum wrote:
> On Sun, Sep 22, 2013 at 10:35 AM, Terry Reedy <tjreedy at udel.edu
> <mailto:tjreedy at udel.edu>> wrote:
>
>     On 9/21/2013 10:30 PM, Guido van Rossum wrote:
>
>         Exceptions in __del__ point to bugs (sometimes in the stdlib) that
>         should be fixed, period. The only reason they do not result in
>         exceptions that are properly bubbled up and catchable is because
>         __del__
>         is called from a DECREF macro which has no return value.
>
>
>     That is clear enough. What fooled me is the word 'ignored', in both
>     the doc and message. How about 'skipped' (for technical reasons)?
>
>
> That's a good point, although I'm not sure 'skipped' is better.

Only slightly ;-). The problem with both words is that they try to say 
two things. What happened, and what Python did about it.

> Maybe use a more neutral verb like 'occurred'?

"Exception occurred in ..." is even better at say what happened.

I think we should then add an explict statement as to what Python did, 
and hint at what the user should do, something like
"Although caught internally, it still indicates a problem."

Otherwise, when no other output follows, as in
...
 > del c
Exception ocurred in: <bound method C.__del__ ...
Traceback (most recent call last):
   File "<pyshell#0>", line 2, in __del__
AttributeError:
 >>>
It may not be completely obvious to a non-expert that the traceback is 
not a 'real' traceback from an exception that was allowed to propagate, 
and that it did not stop execution and cannot be caught.

-- 
Terry Jan Reedy