Unit 09 — Dictionaries & Data

Four original, step-by-step Python lessons. Each includes a worked example, tracing, reflection, and a separate checkable practice task. All lessons keep stable IDs in the 09-dictionaries-and-data/ namespace.

1. Look up information by key — 5 points
2. Count repeated events — 10 points
3. Read a collection of records — 10 points
4. Calculate an inventory order — 15 points

This unit extends the progression in How to Think Like a Computer Scientist; the instructional prose and exercises are original. See curriculum sources.