Review on PSAD 5.5

While I was studying "Problem Solving with Algorithms and Data Structures using Python", I encountered two things that look very interesting. First of all, I became very interested in why Python allows a comma at the end of the list. I could find a interesting discussion on a stackoverflow page. To sum up, it is allowed to make it easier to edit multi-line lists.

Second thing that I caught my attention was that Python has a slice operator. This was also explained on a stackoverflow page and it seem very interesting this kind of operator.