Saltman: Speeding things up #40

First a general comment: I really like this chapter, content and style. Exactly the kind of reading I wish I'd done on week 1, say day 2 of my Python adventure. It will help many.

The code works. I run all of it and got the same results.

Text without the code snippet is ~650 words, just about right.

But it is double that amount with the code; I am not sure if it'll fit, I'd check with @kwinkunks - I wonder if you could aggregate all code into a figure with 4 subplots (a, b, c, d) and use screen captures of the snippets instead of text. Just a thought.