Thank you very much for this, Guido, it was really helpful. I agree: the docs need an improvement to clarify the points you made. I will be able to submit a patch as soon as I wrap up my book. The deadline is soon.
Cheers, Luciano On Sun, Mar 22, 2015 at 7:22 PM, Guido van Rossum <gu...@python.org> wrote: > They're totally different. async() is for those cases where you have > something that's either a coroutine or a Future and what you need is a > Future (e.g. because you want to add a callback). It will return the Future > unchanged but wrap the coroutine in a Task. (Note that Task subclasses > Future so a Task will also be returned unchanged.) > > OTOH create_task() *always* creates a new Task, and the argument must > *always* be a coroutine. It is *nearly* the same as just using Task() -- the > difference is that create_task() may be overridden by certain EventLoop > subclasses to return a task that behaves better with some other framework > (e.g. Tornado). > > Also note that async() calls create_task(), but only when it decides to > create a new task. > > Maybe the docs need an upgrade, please submit a patch. > > On Sun, Mar 22, 2015 at 7:32 AM, Luciano Ramalho <luci...@ramalho.org> > wrote: >> >> I understand these do almost the same thing, and asyncio.async can >> even get a loop keyword argument so it's as flexible as >> loop.create_task, which it uses internally. >> >> So my question is: are both being kept going forward, or is this >> redundancy just a temporary compatibility measure before asyncio.async >> is deprecated? >> >> The docs seem to imply ever-so-slightly that create_task is better and >> async should be used "to support also older Python versions". >> >> Cheers, >> >> Luciano >> >> -- >> Luciano Ramalho >> | Author of Fluent Python (O'Reilly, 2015) >> | http://shop.oreilly.com/product/0636920032519.do >> | Professor em: http://python.pro.br >> | Twitter: @ramalhoorg > > > > > -- > --Guido van Rossum (python.org/~guido) -- Luciano Ramalho | Author of Fluent Python (O'Reilly, 2015) | http://shop.oreilly.com/product/0636920032519.do | Professor em: http://python.pro.br | Twitter: @ramalhoorg
