[Python-Dev] Intention to accept PEP 552 soon (deterministic pyc files)

[Guido van Rossum]

On Sun, Oct 1, 2017 at 1:52 PM, Koos Zevenhoven <k7hoven at gmail.com> wrote:

> On Oct 1, 2017 19:26, "Guido van Rossum" <guido at python.org> wrote:
>
> Your PEP is currently incomplete. If you don't finish it, it is not even a
> contender. But TBH it's not my favorite anyway, so you could also just
> withdraw it.
>
>
> I can withdraw it if you ask me to, but I don't want to withdraw it
> without any reason. I haven't changed my mind about the big picture. OTOH,
> PEP 521 is elegant and could be used to implement PEP 555, but 521 is
> almost certainly less performant and has some problems regarding context
> manager wrappers that use composition instead of inheritance.
>

It is my understanding that PEP 521 (which proposes to add optional
__suspend__ and __resume__ methods to the context manager protocol, to be
called whenever a frame is suspended or resumed inside a `with` block) is
no longer a contender because it would be way too slow. I haven't read it
recently or thought about it, so I don't know what the second issue you
mention is about (though it's presumably about the `yield` in a context
manager implemented using a generator decorated with
`@contextlib.contextmanager`).

So it's really between PEP 550 and PEP 555. And there are currently too
many parts of PEP 555 that are left to the imagination of the reader. So,
again, I ask you to put up or shut up. It's your choice. If you don't want
to do the work completing the PEP you might as well withdraw (once I am
satisfied with Yury's PEP I will just accept it when there's no contender).
If you do complete it I will probably still choose PEP 550 -- but at the
moment the choice would be between something I understand completely and
something that's too poorly specified to be able to reason about it.

--Guido


> -- Koos
>
>
>
> On Oct 1, 2017 9:13 AM, "Koos Zevenhoven" <k7hoven at gmail.com> wrote:
>
>> On Sep 29, 2017 18:21, "Guido van Rossum" <guido at python.org> wrote:
>>
>>
>> PS. PEP 550 is still unaccepted, awaiting a new revision from Yury and
>> Elvis.
>>
>>
>> This is getting really off-topic, but I do have updates to add to PEP 555
>> if there is interest in that. IMO, 555 is better and most likely faster
>> than 550, but on the other hand, the issues with PEP 550 are most likely
>> not going to be a problem for me personally.
>>
>> -- Koos
>>
>
>


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