how translate c++ example to python

I want translate FourPaneViewer from c++ to python as my project framework is based on pyqt5. But now I have the problem as below:

  1. how can I create a subclass of vtkcommand as the example;
  2. how can I show the result by QVTKRenderWindowInteractor as the example is use QVTKWidget.

I tried to get an example for you, but I’m working remote - and graphics forwarding is prevented.
Perhaps try something with vtkViewport? There is an online example on that page as well.