jupyter_client async client

[davidbrochart]

I was wondering if qtconsole should switch to the asynchronous client of jupyter_client. Using the threaded client looks like a hack that was needed prior to asyncio, when asynchronous programming was achieved through Tornado, but is it still necessary today?

[ccordoba12]

Sure, I think that's a good idea. Could you give us a hand with that?

[davidbrochart]

I need to find the time, but at first sight it should be doable using https://github.com/CabbageDevelopment/qasync.