Practical Naive Bayes -- Classification of Amazon Reviews

If you search around the internet looking for applying Naive Bayes classification on text, you'll find a ton of articles that talk about the intuition behind the algorithm, maybe some slides from a lecture about the math and some notation behind it, and a bunch of articles I'm not going to link here that pretty much just paste some code and call it an explanation. So I'm going to try to do a little more here, by hopefully writing and explaining enough, is let you yourself write a working Naive Bayes classifier. There are three sections here. First is setup, and what format I'm expecting your text to be in for the classification. Second, I'll talk about how to run naive Bayes on your own, using slow Python data structures.