Out of the box, it can't be used with websocket, so you'd need to find a Python programmer (or become one yourself) and extend it a little bit. Just out of interest: Which websocket server are you using which speaks the STOMP protocol? Or are you planning to build one?
If you want to go into that direction, feel free to add a ticket. I won't implement it, but I'm happy to accept pull requests and to answer implementation related questions.
Just my two cents (if want to continue this discussion into more detail with the goal of a stompest improvement, I ask you to open a ticket and to transfer this discussion to Github):
async
I just looked into Twisted; it seems to provide an implementation of a websocket transport, cf.
http://stackoverflow.com/questions/4406256/twisted-and-websockets-beyond-echo. Adding a transport other than the TCP/IP standard one isn't too hard, but Twisted has kind of a steep learning curve, and you need to know at least a little something about asynchronous programming.
sync
Here, the separation between transport and protocol is not as perfect as in Twisted, but it's not too difficult to improve that. It is easy to make the make the socket() and select() methods (the socket API) configurable, cf. the discussion in
https://github.com/nikipore/stompest/issues/11. Then I suppose that all you need is a Python implementation of these methods which almost certainly is available.
roll your own client
Also not too difficult, the batteries for the protocol logic are included separately.