For anyone looking for a more usable version of C++/Python interop, I can't recommend Cppyy[0] highly enough. You can use any C++ code/libraries from Python without the need to write any bindings. I created an example project here to test it out[1].
I believe it's no longer the case. The maintainer of Cppyy was cautioning that the Python 3 support was somewhat experimental at the time, but I believe it's officially supported now. Either way, it could have been solved by building from source, but I was feeling lazy :)
0. https://cppyy.readthedocs.io/en/latest/
1. https://github.com/jclay/cppyy-knearestneighbors-example