Even in C++/Java WPILib does not have builtin support for the NavX, you have to install separate software.
I've ported their software over to python and it looks like it works, though I haven't been able to test it comprehensively yet. I'll be polishing it and make a formal release soon.
If you want to look at it, it's in the mxp branch of robotpy-wpilib-utlities:
https://github.com/robotpy/robotpy-w...ities/tree/mxp .. requires master version of robotpy-wpilib.