Dictionaries

New idea

What is Sam's index?

Your phone holds 500 contacts. To call Sam you don't think "Sam is contact number 312". You just look up the name. A list can only find things by position, and most of the time you don't know the position.

A dictionary stores pairs: a key and its value. You write it in curly braces, with a colon between each key and its value: ages = {"sam": 12, "mia": 9}.

You read a value by putting its key in square brackets: ages["sam"] gives 12. Like a real dictionary, you look up the word and get its meaning, without counting pages.