On Sat, May 2, 2015 at 1:18 PM, Arnaud Delobelle firstname.lastname@example.org wrote:
On 1 May 2015 at 20:59, Guido van Rossum email@example.com wrote:
On Fri, May 1, 2015 at 12:49 PM, Ron Adam firstname.lastname@example.org wrote:
Another useful async function might be...
async def yielding(): pass
In a routine is taking very long time, just inserting "await yielding()" in the long calculation would let other awaitables run.
That's really up to the scheduler, and a function like this should be provided by the event loop or scheduler framework you're using.
Really? I was under the impression that 'await yielding()' as defined above would actually not suspend the coroutine at all, therefore not giving any opportunity for the scheduler to resume another coroutine, and I thought I understood the PEP well enough. Does this mean that somehow "await x" guarantees that the coroutine will suspend at least once?
You're correct. That's why I said it should be left up to the framework -- ultimately what you *do* have to put in such a function has to be understood by the framenwork. And that's why in other messages I've used await asyncio.sleep(0) as an example. Look up its definition.
To me the async def above was the equivalent of the following in the 'yield from' world:
def yielding(): return yield # Just to make it a generator
Then "yield from yielding()" will not yield at all - which makes its name rather misleading!