Turn off VTK in OpenCV (unless user is selecting VTK?), as most likely usecase is a python lib, which should not have visualisation.
Don't need OpenCV to be compiled with Python bindings. That would be done at the top-level of this project. i.e. you do not want to replace the Python version of OpenCV already installed in the system.
Taking inspiration from https://github.com/yati-sagade/opencv-ndarray-conversion