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Async I/O for Python 3

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Re: Async I/O for Python 3

#11

Post by pjscott »

rdtsc wrote: post #10

Sigh, another Async framework. Yes it has nice features such can replace the reactor/hub thing. Has futures/promises/deferreds. That has all been done before in Twisted. Yields are cute and there was monocle, I wouldn't say it exactly took off : https://github.com/saucelabs/monocle Twisted has inlineCallbacks that use yields as well. Just import Twisted into stdlib then and use that. I am surprised that gevent was di…

YES. Thank you for saying this. Some of the async code that I maintain uses Twisted and some of it uses Eventlet, and the difference between them is night and day. The code using Eventlet is so much cleaner, so much easier to maintain, and (oddly enough) so much less magical than the Twisted stuff. This was written by the same people, and they're all really good programmers, so the obvious confounding variables are not an issue here. Eventlet and Gevent are just so much better.

Worried about monkey-patching? Then only monkey-patch the parts you need to be asynchronous. Worried about magic that you don't understand? Have a look at the code; the magic is actually pretty straightforward after you've paid a little attention to the man behind the curtain.

If you're interested in async stuff for Python, I urge you to have a look at Eventlet or Gevent.

Re: Async I/O for Python 3

#12

Post by hosay123 »

rdtsc wrote: post #10

Sigh, another Async framework. Yes it has nice features such can replace the reactor/hub thing. Has futures/promises/deferreds. That has all been done before in Twisted. Yields are cute and there was monocle, I wouldn't say it exactly took off : https://github.com/saucelabs/monocle Twisted has inlineCallbacks that use yields as well. Just import Twisted into stdlib then and use that. I am surprised that gevent was di…

Sane is in the eye of the beholder.. gevent looks nice, but I'd be very diffident when it comes to actually supporting it in production. It monkey patches the standard library and messes with CPython internals to achieve what it does, infinitely increasing the chance it will conflict with some other piece of code (for example, that bizarre ancient internal propriety library you're using that started life in Fortran, etc)

In the case of async I'm glad to see a from scratch implementation for the standard library. It's a weird area that necessitates some constructions that there is no really standard Python style for. You only need to look at Twisted and e.g. its method chaining to realize this stuff would need a thorough sanity rework before it ever became standard anyway.

Also, most other implementations take the approach of building their own little world. This is definitely true of Twisted. You write code for Twisted, not for Python. Gevent at least doesn't suffer from this.

Re: Async I/O for Python 3

#15

Post by CoffeeDregs »

Perhaps the video makes more clear the rationale. E.g.

  Possible solution: "Standardizing gevent solves all its problems". 
  One of the responses: "I like to write clean code from scratch".
  Another: "I really like clean interfaces".
So I'd prefer that the BDFL work with the gevent folks to get it cleaned up and integrated while adjusting it to expose a "clean interface".

Perhaps the whole thing will make more sense once Guido provides more detail, but I'm underwhelmed and confused.

Re: Async I/O for Python 3

#16

Post by simeonf »

rdtsc wrote: post #10

Sigh, another Async framework. Yes it has nice features such can replace the reactor/hub thing. Has futures/promises/deferreds. That has all been done before in Twisted. Yields are cute and there was monocle, I wouldn't say it exactly took off : https://github.com/saucelabs/monocle Twisted has inlineCallbacks that use yields as well. Just import Twisted into stdlib then and use that. I am surprised that gevent was di…

>Sigh, another Async framework.

>Yes it has nice features such can replace the reactor/hub thing. Has futures/promises/deferreds. That has all been done before in Twisted.

Yeah but - this will be in stdlib. And I think the hope is one-event-loop-to-rule-them-all will let the various frameworks play nice with each other. For instance - Glyph just mentioned to me that he doesn't use IPython any more to work on Twisted code because IPython now has a Tornado event loop which can conflict with the Twisted code he's playing with...

I don't think the hope is that this will be better than twisted or gevent in terms of implementation (obviously the API will be nicer than twisted given Python 3) just that it will be the standard by virtue of being in stdlib.

Re: Async I/O for Python 3

#17

Post by njharman »

rdtsc wrote: post #10

Sigh, another Async framework. Yes it has nice features such can replace the reactor/hub thing. Has futures/promises/deferreds. That has all been done before in Twisted. Yields are cute and there was monocle, I wouldn't say it exactly took off : https://github.com/saucelabs/monocle Twisted has inlineCallbacks that use yields as well. Just import Twisted into stdlib then and use that. I am surprised that gevent was di…

Did you actually read the slides? Most of your comments and complaints are addressed and sound like non-nonsensical fud in context.

I wasn't a fan of stdlib async until reading these slides.

Re: Async I/O for Python 3

#18

Post by Ixiaus »

hosay123 wrote: post #12
rdtsc wrote: post #10

Sigh, another Async framework. Yes it has nice features such can replace the reactor/hub thing. Has futures/promises/deferreds. That has all been done before in Twisted. Yields are cute and there was monocle, I wouldn't say it exactly took off : https://github.com/saucelabs/monocle Twisted has inlineCallbacks that use yields as well. Just import Twisted into stdlib then and use that. I am surprised that gevent was di…

Sane is in the eye of the beholder.. gevent looks nice, but I'd be very diffident when it comes to actually supporting it in production. It monkey patches the standard library and messes with CPython internals to achieve what it does, infinitely increasing the chance it will conflict with some other piece of code (for example, that bizarre ancient internal propriety library you're using that started life in Fortran,…

I used gevent at first for a project that needed Async I/O and it worked really well, but then I switched to Erlang and I realized how poor a choice Python is for such tasks. The language really needs to be designed from the start for it (like Go, Rust, Erlang &c... Haskell wasn't designed from start for it but because of it's functional purity, bolting it on was "natural" but - it isn't so for Python IMHO).

Re: Async I/O for Python 3

#19

Post by rdtsc »

Ixiaus wrote: post #18
hosay123 wrote: post #12

Earlier quoted context omitted.

Sane is in the eye of the beholder.. gevent looks nice, but I'd be very diffident when it comes to actually supporting it in production. It monkey patches the standard library and messes with CPython internals to achieve what it does, infinitely increasing the chance it will conflict with some other piece of code (for example, that bizarre ancient internal propriety library you're using that started life in Fortran,…

I used gevent at first for a project that needed Async I/O and it worked really well, but then I switched to Erlang and I realized how poor a choice Python is for such tasks. The language really needs to be designed from the start for it (like Go, Rust, Erlang &c... Haskell wasn't designed from start for it but because of it's functional purity, bolting it on was "natural" but - it isn't so for Python IMHO).

Agreed, I am learning Erlang currently as well.
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