A fellow (I will use his name when he gives me permission) has inspired me to finish a python program for generating and using the Denis Berthier extended Sudoku board (four types of sudoku grids) I started this code back in July of 2013 when I was just beginning to learn python. So the code is rather crude, but is all in one file and seems to work. I would be glad to email it to anyone who would like to try it. It does not have a GUI, but is simply a console application. I am working on a python GUI that now just displays the four grids with pencil marks, but has no logic behind it yet.
I have Version 1.0 of the console version which I have tested (crudely at this point) where it can run under python 2.7.11 or 3.5.1. I will email it to anyone who wishes to 'play' with it. Richard Goodrich's email is: firstname.lastname@example.org (richardgoodrich at gmail dot com)