Currently, you can only set the subdomain for a Community Cloud app. If you want to use your own top-level domain, you’ll need to host the app somewhere else. You can use an iframe if you want to host a static site somewhere else to show your Community Cloud app, but that does obfuscate paths and query params.
If you want to host a static website somewhere else that just has an iframe to your Community Cloud app, you should be able to do that almost anywhere. That’s just plain HTML. However, if you want to actually host your app directly from another domain, you’d need a host that can run the Python server.