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Re: How the heck does async/await work in Python 3.5

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On Tue, Feb 23, 2016 at 9:50 AM, Sven R. Kunze <srkunze@mail.de> wrote:
> On 23.02.2016 01:48, Ian Kelly wrote:
>>
>> On Mon, Feb 22, 2016 at 3:16 PM, Sven R. Kunze <srkunze@mail.de> wrote:
>>>
>>> Is something like shown in 12:50 ( cout << tcp_reader(1000).get() )
>>> possible
>>> with asyncio? (tcp_reader would be async def)
>>
>> loop = asyncio.get_event_loop()
>> print(loop.run_until_complete(tcp_reader(1000)))
>
>
> I see. Thanks. :)
>
> How come that Python (compared to C++) needs much more boilerplate to use
> async programming? Historically, it was the other way round.

It's not entirely clear to me what the C++ is actually doing. With
Python we have an explicit event loop that has to be started to manage
resuming the coroutines. Since it's explicit, you could easily drop in
a different event loop, such as Tornado or curio, if desired. If your
coroutine never awaits anything that isn't already done then
technically you don't need an event loop, but at that point you might
as well be using ordinary functions.

The C++ on the other hand seems to be doing something implicit at the
compiler level to make everything happen automatically inside the
future.get() call, but I don't know what that is.

You could wrap up the boilerplate in Python if you like:

def get(coro, loop=None):
    if loop is None:
        loop = asyncio.get_event_loop()
    return loop.run_until_complete(coro)

print(get(tcp_reader(1000)))

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How the heck does async/await work in Python 3.5 Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-02-17 22:08 +0000
  Re: How the heck does async/await work in Python 3.5 Steven D'Aprano <steve@pearwood.info> - 2016-02-20 13:36 +1100
    Re: How the heck does async/await work in Python 3.5 Rustom Mody <rustompmody@gmail.com> - 2016-02-19 21:24 -0800
      Re: How the heck does async/await work in Python 3.5 Rustom Mody <rustompmody@gmail.com> - 2016-02-19 21:34 -0800
        Re: How the heck does async/await work in Python 3.5 Paul Rubin <no.email@nospam.invalid> - 2016-02-19 22:44 -0800
          Re: How the heck does async/await work in Python 3.5 Steven D'Aprano <steve@pearwood.info> - 2016-02-21 18:17 +1100
            Re: How the heck does async/await work in Python 3.5 Paul Rubin <no.email@nospam.invalid> - 2016-02-20 23:34 -0800
      Re: How the heck does async/await work in Python 3.5 Ian Kelly <ian.g.kelly@gmail.com> - 2016-02-20 00:48 -0700
      Re: How the heck does async/await work in Python 3.5 Chris Angelico <rosuav@gmail.com> - 2016-02-20 18:57 +1100
      Re: How the heck does async/await work in Python 3.5 Ian Kelly <ian.g.kelly@gmail.com> - 2016-02-20 01:14 -0700
      Re: How the heck does async/await work in Python 3.5 Chris Angelico <rosuav@gmail.com> - 2016-02-20 19:49 +1100
      Re: How the heck does async/await work in Python 3.5 Ian Kelly <ian.g.kelly@gmail.com> - 2016-02-20 02:11 -0700
      Re: How the heck does async/await work in Python 3.5 Ian Kelly <ian.g.kelly@gmail.com> - 2016-02-20 02:21 -0700
    Re: How the heck does async/await work in Python 3.5 Christian Gollwitzer <auriocus@gmx.de> - 2016-02-20 07:53 +0100
      Re: How the heck does async/await work in Python 3.5 "Sven R. Kunze" <srkunze@mail.de> - 2016-02-22 23:16 +0100
      Re: How the heck does async/await work in Python 3.5 Ian Kelly <ian.g.kelly@gmail.com> - 2016-02-22 17:48 -0700
      Re: How the heck does async/await work in Python 3.5 "Sven R. Kunze" <srkunze@mail.de> - 2016-02-23 17:50 +0100
      Re: How the heck does async/await work in Python 3.5 Ian Kelly <ian.g.kelly@gmail.com> - 2016-02-23 10:37 -0700
      Re: How the heck does async/await work in Python 3.5 "Sven R. Kunze" <srkunze@mail.de> - 2016-02-23 20:42 +0100
      Re: How the heck does async/await work in Python 3.5 "Sven R. Kunze" <srkunze@mail.de> - 2016-02-23 22:05 +0100
      Re: [Python-ideas] How the heck does async/await work in Python 3.5 "Joao S. O. Bueno" <jsbueno@python.org.br> - 2016-02-23 18:25 -0300
      Re: [Python-ideas] How the heck does async/await work in Python 3.5 Paul Moore <p.f.moore@gmail.com> - 2016-02-24 09:59 +0000
      Re: [Python-ideas] How the heck does async/await work in Python 3.5 Victor Stinner <victor.stinner@gmail.com> - 2016-02-24 11:01 +0100
      Re: [Python-ideas] How the heck does async/await work in Python 3.5 王珺 <wjun77@gmail.com> - 2016-02-24 18:40 +0800
        Re: [Python-ideas] How the heck does async/await work in Python 3.5 Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2016-02-25 10:00 +1300
          Re: [Python-ideas] How the heck does async/await work in Python 3.5 王珺 <wjun77@gmail.com> - 2016-02-25 08:40 +0800
          Re: [Python-ideas] How the heck does async/await work in Python 3.5 Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2016-02-24 20:37 -0500
      Re: [Python-ideas] How the heck does async/await work in Python 3.5 Tem Pl <rtempl31@gmail.com> - 2016-02-24 06:39 -0800
        Re: [Python-ideas] How the heck does async/await work in Python 3.5 Marko Rauhamaa <marko@pacujo.net> - 2016-02-24 17:23 +0200
          Re: [Python-ideas] How the heck does async/await work in Python 3.5 Ian Kelly <ian.g.kelly@gmail.com> - 2016-02-24 08:41 -0700
            Re: [Python-ideas] How the heck does async/await work in Python 3.5 Marko Rauhamaa <marko@pacujo.net> - 2016-02-24 18:13 +0200
              Re: [Python-ideas] How the heck does async/await work in Python 3.5 Ian Kelly <ian.g.kelly@gmail.com> - 2016-02-24 09:47 -0700

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