Yes, the client application connecting to the websocket server can be an user using an interactive console, a python application or any other software in any language.
But if your objective is to have a webpage then no, unfortunately web browsers can only run javascript, if you really dislike javascript you may even use some other language that can transpile to js such as coffescript or typescript, but at the end the browser will still run javascript.
I still dream of the day that we will be able to run python on the browser