This is the code that I've written while reading the great book Python 3 Object-Oriented Programming - Third Edition by Dusty Phillips.
The original repo with the code can be found here.
N.B.: BTW, I've just realized today (June 21, 2021) that a 4th edition is close (on sale next month, July'21)... XD. The repo corresponding to the 4th ed. can be found here.