Lists and dictionaries
Lists and dictionaries together cover most needs: a list of dictionaries is the standard shape for records, one dictionary per row.
Python for Kids · Class 8 · Module 2 of 9
Data Structures
Data has a shape. Match the shape and the code almost writes itself.
8 sessionsSessions 9–16
4 weeksTypical pace
Foundation to IntermediateLevel
Class 8Python & Coding
The big idea
Students compare lists, dictionaries and sets, learn what each is genuinely good at, and practise nesting them to model real information such as a library, an inventory or a timetable.
Why it matters
Structure choice is where beginners and capable programmers visibly diverge. The right structure turns a hard problem into an easy one.
Unpacked
What you will actually learn
Three core ideas, each taught with worked examples and then practised until it feels obvious.
Sets
Sets store unique values and answer membership questions instantly. They are the fastest way to remove duplicates or find what two groups share.
Nested structures
Nested structures let one object hold another — a book dictionary containing a list of borrowers, and each borrower a dictionary of their own.
Did you know?
Checking whether an item is in a set of a million values takes microseconds. The same check on a list of a million may need to inspect every single one.
Common mix-up
“Sets are just lists without duplicates.” They are also unordered, which means you cannot ask for “the third item” at all.
Session by session
Your 8-session journey
Sessions 9–16 of the 72-session year, at two one-hour sessions per week.
- 1
Warm-up and big picture
Where this module fits, what you will build, and a hands-on starter that gets everyone curious about lists and dictionaries.
- 2
Lists and dictionaries
Guided teaching on lists and dictionaries, worked through together with the teacher.
- 3
Lists and dictionaries — practice lab
Independent practice, small challenges and one deliberate mistake to diagnose.
- 4
Sets
Guided teaching on sets, building directly on the previous two sessions.
- 5
Sets — practice lab
Applied tasks that combine lists and dictionaries and sets in one piece of work.
- 6
Nested structures
Nested structures introduced and practised, completing the toolkit needed for the project.
- 7
Project build
Guided build session for the module project: Library catalogue.
- 8
Test, present and reflect
Finish, test against the checklist, present the work and explain the decisions behind it.
Project lab
Library catalogue
Every module ends with something the student built themselves and can demonstrate. This is the piece that goes into their portfolio and gets explained out loud at the end of session 16.
Try this at home
Model your school library as nested data, then answer three questions with code: which books are out, who has most, and which are never borrowed.
It is finished when
- It works from start to finish without breaking
- You can explain every part of it in your own words
- You tested it and improved at least one thing afterwards
- Someone else used or understood it without your help
By the end of this module
Students finishing Module 2 can:
- Explain and use lists and dictionaries without prompting
- Explain and use sets without prompting
- Explain and use nested structures without prompting
- Build and finish library catalogue
- Test your own work and correct what you find
- Talk an adult through what you made and why
Word bank
The vocabulary introduced here, in plain language:
- set
- An unordered collection of unique values.
- nesting
- Placing one data structure inside another.
- record
- One complete entry in a collection of data.
Module challenge
Think you have got this?
0 XPLevel 1 · Curious Beginner
6 quick questions drawn from this module — vocabulary, the project you build, and a myth-or-fact round. Every wrong answer explains itself, so a mistake still teaches you something.
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