Is the Tuples & Sets lesson free?

Yes. The first 5 lessons on PyRun are free forever — no signup, no card. Tuples & Sets runs real Python in your browser via Pyodide.

How long does the Tuples & Sets lesson take?

About 6 minutes end-to-end. It's a hands-on lesson — you read a paragraph, edit the code, and run it in the same tab.

Do I need to install Python to try the Tuples & Sets lesson?

No install required. PyRun runs real CPython in your browser via Pyodide (Python compiled to WebAssembly). Works on Chrome, Firefox, Safari, and Edge — desktop or mobile.

What level is the Tuples & Sets lesson?

Beginner level. No prior Python required — good starting point.

← All lessons

Beginner·6 min·basics · tuples · sets

Tuples & Sets

You’ll be able to

Choose between mutable lists, immutable tuples, and unique sets
Unpack tuples into multiple variables in one line
Perform set operations: union, intersection, difference
Convert between list, tuple, and set as needed

Why this matters

Tuples are the default return type for multi-value functions (divmod, os.path.split) and the only hashable sequence, making them dict-key material. Sets solve dedup and membership tests in O(1), a favorite interview trick.

Common pitfalls

Writing t = (1) for a single-item tuple. That is an int; the correct form is t = (1,) with a trailing comma.
Trying to mutate a tuple: t[0] = 5 raises TypeError. Convert with list(t) if you need mutation.
Assuming sets preserve order. They do not; use dict.fromkeys(lst) if you need order-preserving dedup.

Tuples

(1, 2, 3) — like a list, but immutable (can't change after creation)
Useful for fixed records: point = (x, y), (name, age)
Unpacking: a, b = (1, 2) is one of Python's loveliest features

Sets

{1, 2, 3} — unordered collection of unique values
O(1) membership check (much faster than a list for "is x in this?")
Set algebra: | union, & intersect, - difference

Try it

Deduplicate a list with list(set(items)).
Find words that appear in both "the quick brown fox" and "the lazy dog".

Practice

3 graded exercises

Write the code, click Check. We’ll tell you exactly what to fix.

Progress0 / 3

Exercise 1
Given point = (7, 24), unpack it into variables x and y, then print exactly x=7, y=24.
Exercise 2
The list items = ["a", "b", "a", "c", "b", "d"] has duplicates. Print how many unique values it has — expected: 4.
Exercise 3
Given two sets of skills, me = {"python", "sql", "docker"} and job = {"python", "aws", "docker"}, print the sorted list of shared skills — expected: ['docker', 'python'].

← PreviousSlicing Next →Dictionaries

Tuples & Sets

You’ll be able to

Choose between mutable lists, immutable tuples, and unique sets
Unpack tuples into multiple variables in one line
Perform set operations: union, intersection, difference
Convert between list, tuple, and set as needed

Why this matters

Common pitfalls

Writing t = (1) for a single-item tuple. That is an int; the correct form is t = (1,) with a trailing comma.
Trying to mutate a tuple: t[0] = 5 raises TypeError. Convert with list(t) if you need mutation.
Assuming sets preserve order. They do not; use dict.fromkeys(lst) if you need order-preserving dedup.

Tuples

(1, 2, 3) — like a list, but immutable (can't change after creation)
Useful for fixed records: point = (x, y), (name, age)
Unpacking: a, b = (1, 2) is one of Python's loveliest features

Sets

{1, 2, 3} — unordered collection of unique values
O(1) membership check (much faster than a list for "is x in this?")
Set algebra: | union, & intersect, - difference

Try it

Deduplicate a list with list(set(items)).
Find words that appear in both "the quick brown fox" and "the lazy dog".

Practice

3 graded exercises

Write the code, click Check. We’ll tell you exactly what to fix.

Progress0 / 3

Exercise 1
Given point = (7, 24), unpack it into variables x and y, then print exactly x=7, y=24.
Exercise 2
The list items = ["a", "b", "a", "c", "b", "d"] has duplicates. Print how many unique values it has — expected: 4.
Exercise 3
Given two sets of skills, me = {"python", "sql", "docker"} and job = {"python", "aws", "docker"}, print the sorted list of shared skills — expected: ['docker', 'python'].