asyncio, socket and select

[fmafma]

Hi!

In Peter's documentation about asyncio and socket:
https://github.com/peterhinch/micropython-async/blob/master/v3/docs/TUTORIAL.md#76-socket-programming
it is mentionned that there is an example using select in client_server dir:
https://github.com/peterhinch/micropython-async/blob/master/v3/as_drivers/client_server/userver.py
If the select module is imported, I don't see it used anywhere.

Did I miss something?

Thanks.

[sosi-deadeye]

The function asyncio.start_server binds the socket and if a new connection is made, the async function run_client is called with an instance of StreamReader and StreamWriter. If you await for data, the control is given back to the even loop. The even loop polls. I guess it uses select internally. In the second example, the import of select is not required.

[fmafma]

But it is written:

The userver application uses select.poll explicitly to poll the server socket. The client sockets use it implicitly in that the asyncio stream mechanism employs it.

I would like to understand how to use select.poll, as I need to work at socket level, and not with streams...

[peterhinch]

Apologies. The tutorial was written for uasyncio V2, then updated for V3. The comment about select and the example import are outdated. I will update.

For examples that really use select see this official example and this unofficial code. Also this tutorial text.

[fmafma]

Thank you for the links!

[peterhinch]

I've amended the tutorial text. Thanks for pointing out the error.