Python JMS Equivalent?

I’m thinking through an implementation that I’d like to scale some day. Essentially it’s a message processing system with a small bit of state to pass around. Mostly it’s a matter of handing messages off between various workers.

In Java world I’d do this with threads. If I wanted to think across boxes I’d throw in some sort of persistent queue, likely JMS.

But I’m in the Python world. I could do threads (btw, how well do threads work in Python in both windows and linux?), but I’m on a non-threads kick at the moment and would like to go the multi-process/message passing route.

What I’m looking for is a JMS equivalent for Python - a persistent, reliable message passing system with a clean API that can be used on a single machine/single processor system just as well as on a multi-machine/multi-processor network of systems.

I looked briefly - I could do something with xmpp, there’s spread, or I could put the queue in a database. But none of them are satisfactory.

How are people doing persistent queues in Python? Is there a JMS like device?