[takeda]

There's a way, but I did not do it outside of just POC. It's actually possible to compile legacy code using Cython and import it to python 3, then I suppose you could convert one file at a time.

It's possible that this might be more work that if you would use pylint, mypy, python-future. Also it probably won't work if your code tries to be clever and does some import hacking (although who knows, maybe it still would work)