[Python-Dev] PEP 409 update [was: PEP 409 - final?]

[Guido van Rossum]

On Thu, Feb 2, 2012 at 6:49 PM, Nick Coghlan <ncoghlan at gmail.com> wrote:
> On Fri, Feb 3, 2012 at 12:42 PM, Ethan Furman <ethan at stoneleaf.us> wrote:
>> Nick Coghlan wrote:
>>>
>>> FWIW, I expect the implementation will *allow* "raise exc from
>>> Ellipsis" as an odd synonym for "raise exc".
>>
>>
>> Are we sure we want that?  Raising from something not an exception seems
>> counter-intuitive (None being the obvious exception).
>
> It isn't so much a matter of wanting it as "Is it problematic enough
> to put any effort into preventing it?" (since allowing it is a natural
> outcome of the obvious implementation).

I would say yes we want that. It would be strange if you couldn't
reset a variable explicitly to its default value. I don't expect
people to do this often. But somebody might want to do a deep copy of
an exception (with some systematic change), or there might be other
reasons. I'm sure a few Python zen items apply here. :-)

-- 
--Guido van Rossum (python.org/~guido)