Global vs local variable

[mpd]

you can have simple, extensible examples without using classes.

It may be true, but this is for expert programmers, and there is little benefit in not using classes.

I think you've lost track of the OP's goals:

I'm a teacher and I just began learning Python so I can show some tips to my students.

I'm not suggesting the OP build an extensible game framework without using classes. I am suggesting that, when writing small programs to "show tips to students", you can -- and probably should -- do it without classes. After all, if the students have not seen a computer program before (the OP wasn't clear about that but I'm guessing this is the case), they're going to have to learn what a variable is, what s function is, what a loop is, etc.

Why add classes to that out of the gate when you don't have to?

Well, I don't think classes are difficult to understand and to use.

Neither do I but when I was a CS teaching assistant and tutor I encountered a lot of people for whom classes were very difficult to wrap their heads around.