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From: Ian Kelly <ian.g.kelly@gmail.com>
Date: Mon, 16 Mar 2015 09:26:26 -0600
Subject: Re: generator/coroutine terminology
To: Python <python-list@python.org>
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On Mon, Mar 16, 2015 at 9:09 AM, Marko Rauhamaa <marko@pacujo.net> wrote:
> Ian Kelly <ian.g.kelly@gmail.com>:
>
>> For generators, the descriptive keyword ("yield") could be buried
>> *anywhere* in that block. One can glance at a generator function and
>> fail to notice that it is a generator function. This is the one that
>> really bugs me about reuse of "def", although you are correct that
>> this is a case where practicality has won over purity.
>
> I don't think that's all that big of a deal even though I will readily
> admit having stumbled on it early on. I removed the last "yield"
> statement from a generator expecting it to keep on being a generator.
> Thus, you have to do things like:
>
>    def nothing():
>        if False:
>            yield None
>
> The "pass" and "global" statements make me think it might be more
> Pythonic to have separate syntax for the special case:
>
>    def nothing():
>        yield not

My (limited) experience with asyncio is that it also makes this a bit
worse. I write a function intended to be a coroutine invoked from
coroutines using "yield from", and then I realize that it's not a
coroutine because it never uses "yield from" itself. Or inversely I
write a normal utility function that is called from coroutines, then
later add a "yield from" to it, and now I have to go back and revise
every place where it's called to make those use "yield from" as well.