[Python-ideas] PEP 530: Asynchronous Comprehensions

[Sven R. Kunze]

On 06.09.2016 20:37, Nick Coghlan wrote:
> On 7 September 2016 at 04:24, Sven R. Kunze <srkunze at mail.de> wrote:
>> Python async community wants you to write everything twice: for the sync and
>> async case. And don't dare to mentioned code sharing here. They will rip you
>> apart. ;)
>>
>> Just kidding. Of course would it be great to write code only once but Yury
>> want to preserve well-paid Python dev jobs in the industry because
>> everything here needs to be maintained twice then. ;)
> Sven, this is not productive, not funny, and not welcome. Vent your
> frustrations with the fundamental split between synchronous and
> explicitly asynchronous software design elsewhere.

Don't make a mistake here, Nick. I take this with some humor as it does 
not concern me in production.
It's interesting to see though that people new to the discussion detect 
this obvious issue very fast.

>
>> No really, I have absolutely no idea why you need to put that "async" in all
>> places where Python can detect automatically if it needs to perform an async
>> iteration or not. Maybe, Yury can explain.
> As Anthony already noted, the "async" keyword switches to the
> asynchronous version of the iterator protocol - you use this when your
> *iterator* needs to interact with the event loop, just as you do when
> deciding whether or not to mark a for loop as asynchronous.

Of course "async" switches to async mode. But that was not the question. 
I asked WHY that's necessary not what it does. I already noted that 
Python can detect when to make the switch without a marker. And you fail 
to explain where the issue with this point of view is.


Sven

PS: Nick, I noted that while replying, my mail client made me responding 
to you and the list as cc. Is there something wrong with my config or is 
this deliberate on your part?