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Ask HN: Starting a new Python project with async networking

1 points by defen ↗ HN
Surveying the async networking landscape for Python has me a bit overwhelmed. There's raw async/await in 3.5+, curio, asyncio, gevent, tornado, stackless, and probably others. If you were starting a new project today, without concern for backward compatibility, what would you use? Python 2.x or 3.x solutions please; I know about Erlang/Go/Node but they aren't a good fit for this project.

6 comments

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eesmith
I would use curio to experiment with the concepts because it, unlike the others, isn't based on event-loops, callbacks, futures, etc. This makes it easier to understand what async can become.

Then I would likely switch to gevent or tornado, because more people are involved in those projects.

itamarst
There's an event loop underneath, even if it's not directly exposed.
eesmith
Isn't based on exposing an event loop, etc. API to the user.
itamarst
1. Python 2 is EOL in 2020, don't use it for new projects.

2. async/await it just an API layer on top of a framework. Thus there is no such thing as raw async/await, it has to be used with a framework of some sort (e.g. Python's built-in asyncio).

3. gevent patches the socket library. Terrible idea. Don't use it.

4. What protocols do you need? Twisted probably has the most implemented, but asyncio and tornado have a bunch too, and not always the same ones.

defen
Thanks.

Protocols - HTTP + some custom stuff on top of TCP.

itamarst
I'd personally use Twisted, but I'm biased insofar as I helped develop it. It has both equivalent of Javascript promises (called Deferreds) and ability to interact with them using async/await if you like that idiom more (http://twistedmatrix.com/documents/current/core/howto/defer-...).

But that's just me.

Given limited protocol needs, I suggest skimming docs for asyncio, Twisted, and Tornado and seeing which seems to make the most sense to you. For Twisted HTTP client and server to look at are Treq (https://treq.readthedocs.io/en/release-17.8.0/) and Klein (https://klein.readthedocs.io/en/latest/).