We’ve been Eventstore users for a few years. Most of our systems use a library called AtomicPuppy, which is a service activator that works by polling streams and calling a function for each new event.
It’s a bit of a pain to test, and while it’s fine for latency-tolerant event driven systems, it’s not great for eventsourcing or high throughput. We’ve also got another lib which we’re testing out in production: photon-pump https://github.com/madedotcom/photon-pump
Photon Pump is intended to be a fast, simple to use TCP client for Python, built using asynchronous generators. There’s a lot of work to do, but the basic use-cases are working for those who want to live on the edge.