Day 16 · Chapter · ~11m

Lists, Dicts & Tuples

Lists, dictionaries, and working with data at scale.

One Variable at a Time Won't Cut It Anymore

You've been working with individual pieces of data — one name, one number, one condition at a time. That works for examples. It doesn't work for the real world.

Your boss sends you a file with 10,000 customer records. You need to filter, sort, and summarize them. One variable per customer? That's 10,000 variables. Obviously not.

This week you'll learn the data structures that make Python powerful: lists and dictionaries. A list holds thousands of items in one variable. A dictionary lets you look up any value instantly — like VLOOKUP, but without the headaches.

By Friday, you'll process real datasets the way professional developers do.

Practice your skills

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