Sample code to teach OpenGL ray tracing in Python

#1

As a part of my duties I need to prepare a demo, where one of the elements is simple ray tracing demonstration in Python using OpenGL.
I need a simple scene, written in OpenGL, that requires ray tracing to occur. Something like one ball here:

Does anyone have simple ray tracing demo written in Python with OpenGL?

I’ve tried to write it on my own, but I do not understand simple lighting modification to call it ray tracing.