Let's play a game. 

I'll give you a couple of Python concepts and you scream "STOP!" as soon as you feel confident enough to explain the concept to an audience. Ready?

Let's start with the first:

Namespaces!

... Nothing? Okay, what about this:

Generators!

... Silence - What about the next one?

Closures and Decorators!

... ???? 

Iterators, Iterables, and Itertools!

... Okay, we seriously need to study those four concepts.

Let's get it done in four short and punchy lessons, shall we?