Find relative location changes of camera using OpenCV (python)

We are evaluating candidates for a larger project and would like to have a very simple demonstration of tracking camera position changes using OpenCV in real time. We are looking for a clean and easily understandable python script with comments. We would like to have a script that displays a real-time feed with overlaid positional changes in camera location. This will be used for a drone positioning project. Monocular or binocular solutions are acceptable.