try..except with empty exceptions

Chris Angelico rosuav at gmail.com
Sat Apr 11 22:04:53 CEST 2015


On Sun, Apr 12, 2015 at 4:49 AM, Ian Kelly <ian.g.kelly at gmail.com> wrote:
> On Apr 11, 2015 5:06 AM, "Steven D'Aprano"
> <steve+comp.lang.python at pearwood.info> wrote:
>>
>> Yes, I agree that Python's behaviour here is better than the alternative.
>> Having "except ()" catch nothing is consistent with the behaviour with
>> other tuples, so I'm okay with that. But it still surprised me :-)
>
> There's another alternative that I haven't seen suggested yet. An empty
> tuple could be considered an indication of a programming error and raise a
> chained ValueError.

Not really a lot of point. Just as with isinstance, an empty tuple
simply matches nothing. Why go to the effort of rejecting it?

ChrisA



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