[Python-ideas] except expression

[Chris Angelico]

On Wed, Feb 19, 2014 at 6:25 PM, Paul Moore <p.f.moore at gmail.com> wrote:
> On 19 February 2014 00:10, Steven D'Aprano <steve at pearwood.info> wrote:
>> x = d1[key] except K d2[key] except K 0
>>
>>
>> which by the way looks horrible without the colons (sorry Paul, you have
>> not convinced me that the Tim Peters prohibition on grit applies here).
>
> While I did say later on yesterday that I'd become less uncomfortable
> with the except Whatever: form, I was never advocating just removing
> the colons - pick your favourite keyword-based proposal and compare
> with that if you want to see what I was talking about.
>
> But that ship has sailed, for better or worse, and it looks like the
> except-colon form is the winner. So be it.

The except-colon form is *my* currently-preferred spelling. But when
Guido took a quick look at it, he didn't like the colon form, and his
preference makes a lot more difference than mine :) It remains to be
seen whether the PEP convinces him one way or the other.

Have you a preferred keyword-based proposal? Does it use an existing
keyword or create a new one? The floor is yours, Paul: sell me your
keyword :) Bear in mind, I used to be in favour of the "expr except
Exception pass default" form, so it shouldn't be too hard to push me
back to there.

ChrisA