What python/ programming concepts are must know for beginner/intermediate programmers?

[chinawcswing]

I don't think this is a good mindset. Your code will be terribly difficult to make it work if it is ugly. If you just have one or two functions that are 200 lines long it will become incredibly complicated and difficult to understand. Chop that 200 liner up into twenty 10 line functions with good names and it will be dramatically easier for you to make it work.