How to use async await in python falcon?

I am looking for example of using async await features of python 3. I am using falcon framework for building rest api. Can’t figure out how to use async await with it.

Please help me, by providing some examples, maybe with other frameworks.

Thank you!

Answer

Update: as of Falcon 3.0, the framework supports async / await via the ASGI protocol.

In order to write async Falcon code, you need to use the ASGI flavour of App, for instance:

import http

import falcon
import falcon.asgi


class MessageResource:
    def __init__(self):
        self._message = 'Hello, World!'

    async def on_get(self, req, resp):
        resp.media = {'message': self._message}

    async def on_put(self, req, resp):
        media = await req.get_media()
        message = media.get('message')
        if not message:
            raise falcon.HTTPBadRequest

        self._message = message
        resp.status = http.HTTPStatus.NO_CONTENT


app = falcon.asgi.App()
app.add_route('/message', MessageResource())

Assuming the above snippet is saved as test.py, the ASGI application can be run as

uvicorn test:app

Setting and retrieving the message with HTTPie:

$ http PUT http://localhost:8000/message message=StackOverflow
HTTP/1.1 204 No Content
server: uvicorn

$ http http://localhost:8000/message 
HTTP/1.1 200 OK
content-length: 28
content-type: application/json
server: uvicorn

{
    "message": "StackOverflow"
}

Note that when using the ASGI flavour of Falcon, all responders, hooks, middleware methods, error handlers etc must be awaitable coroutine functions, as the framework does not perform any implicit wrapping or scheduling in an executor.

See also Falcon’s ASGI tutorial.