Lesson 17 — Mini project: unique words

Mini project: a tiny word-statistics tool

Real text is messy: "The" and "the" should count as one word, and "dog." should not differ from "dog". Normalise first: lowercase everything and strip punctuation. Then combine structures: a set for unique words and a Counter for frequencies.

"Dog.".lower().strip(".,!?")   # "dog"

Why it matters: search engines, spam filters and AI language models all start with exactly this kind of text clean-up.