[Python-ideas] exception instantiation philosophy and practice [was: Let try-except check the exception instance]

[Guido van Rossum]

On Thu, May 31, 2018 at 7:49 AM, Ethan Furman <ethan at stoneleaf.us> wrote:

> On 05/31/2018 07:36 AM, Nick Coghlan wrote:
>
> The exception machinery deliberately attempts to avoid instantiating
>> exception objects whenever it can, but that gets
>> significantly more difficult if we always need to create the instance
>> before we can decide whether or not the raised
>> exception matches the given exception handler criteria.
>>
>
> Why is this?  Doesn't the exception have to be instantiated at some point,
> even if just to print to stderr?
>

Not if it gets caught and ignored.

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