Here's the work-in-progress branch:
https://github.com/krzema12/kotlin-python/commits/python-stdlib but I'd have to re-read the changes to remind myself what's the status. I reached a point where compilation works, but the output misses lots of stuff. I think you can try reading the commits and the cumulative diff from python-backend branch to this WIP branch tip, and maybe you'll manage to make some sense out of it :)