Python Basics · Data Structures · Lesson 18 of 36
Sets
Concept
Sets
Sets store unique, unordered values, useful for removing duplicates or checking membership quickly.
Checking whether a value is in a set with in is much faster than checking a list, especially as the collection grows large.
- Explain the core idea behind Sets.
- Predict output before running a change.
- Test one realistic and one unusual input.
- Use the result to make the next decision.
- 1. Read one concept.
- 2. Change the example.
- 3. Run, compare, and explain.
- 4. Complete the challenge below.
Self-check before continuing
Without looking at the example, describe what changes when you modify one input in Sets. Then reopen the editor and prove your explanation with a small test.
You are ready to continue when you can predict, test, and explain the result.
Your turn
Create a set from a list with duplicate values and print its length.
Ask about this lesson or your next move. The guide explains the path without taking the work away from you.
Ready for the next lesson?
Mark this lesson complete when you have finished the exercise.
Console