I’ve seen several questions on how to learn Python, but most of them were from folks who were looking to start programming for the first time. I don’t need a tutorial that will tell me what a string is, but I need one that can tell me how to make a string in Python. Any help on some good sources to look through? Bonus points if the source is free 
I’ve got a good grasp on C#, my first programming language. I know a reasonable number of tricks and techniques and have written a few programs, mostly for scientific . Now I’d like to branch out and understand OOP, and Python seems like a good direction for me 
.