[Python-Dev] PEP 463: Exception-catching expressions

[Ethan Furman]

On 02/21/2014 05:21 PM, Steven D'Aprano wrote:
> On Sat, Feb 22, 2014 at 01:15:13PM +1300, Greg Ewing wrote:
>>
>> With an except expression, it could be written:
>>
>>     result = computation(int(arg)
>>        except ValueError: abort("Invalid int"))
>
> Nice example! Except I'd lay the code out a bit better to emphasise
> which part is being guarded:
>
>      result = computation(
>                   int(arg) except ValueError: abort("Invalid int")
>                   )
>
> Actually, not quite so nice as I first thought, since you're relying on
> the side-effects of abort() rather than returning a value.

Think of it rather as transforming the exception to be more useful.

--
~Ethan~