Tuples

Big idea

A tuple is like a list that can't be changed. Use one for a small, fixed group of values that belong together — a point (x, y), a date, a name and an age.

Making a tuple

Tuples use round brackets (or just commas):

point = (3, 4)
person = ("Ada", 36)
print(point[0], point[1])
print(len(person))
print(type(point))

output
3 4
2
<class 'tuple'>

Reading works just like a list: indexing, slicing, len, in, looping.

Can't be changed

point = (3, 4)
point[0] = 10
print(point)

output
(10, 4)

Tuples are immutable — point[0] = 10 raises a TypeError. Make a new tuple instead: point = (10, point[1]).

That's the point of a tuple: a value that can't change by accident, the way a list can when it's shared.

Unpacking

Pull a tuple apart into separate names in one line:

person = ("Grace", 85)
name, age = person
print(name)
print(age)

a, b = 1, 2
a, b = b, a
print(a, b)

Grace
85
2 1

a, b = b, a is the Python way to swap two variables — no temporary variable needed. The right side builds the tuple (2, 1) first, then it's unpacked into a and b.

Returning several values

Tuples are how a function hands back more than one result (you'll write functions soon):

lowest, highest = min(scores), max(scores)
quotient, remainder = divmod(17, 5)    # (3, 2)

A one-item tuple needs a comma

not_a_tuple = (5)
a_tuple = (5,)
print(type(not_a_tuple))
print(type(a_tuple))

output
<class 'int'>
<class 'tuple'>

List or tuple?

• List — a collection that grows or changes: tasks, scores, search results.
• Tuple — a fixed record: coordinates, RGB colours, a (name, score) pair.

Watch it

Think of it like

A list is a notebook you keep writing in. A tuple is a printed ticket: seat 14, row F, 7:30pm — fixed once it's issued.

Key terms

• Tuple — An ordered, unchangeable collection: (1, 2).
• Unpacking — Assigning the items of a tuple to several names at once.
• Immutable — Can't be changed after it's made.