Tuples in Python

Introduction

A tuple is an immutable, ordered sequence — like a list that can never be changed. This immutability makes tuples faster, hashable, and semantically meaningful.

Creating Tuples

empty = ()
point = (3, 4)
person = ("Alice", 30, "Engineer")

# Parentheses optional
coords = 10, 20

# Single element tuple NEEDS comma
single  = (42,)       # Tuple
not_tuple = (42)      # Just integer 42!

Packing & Unpacking

point = 3, 4      # Packing
x, y = point      # Unpacking
print(x, y)       # 3 4

# Extended unpacking
first, *rest = (1, 2, 3, 4, 5)
print(rest)   # [2, 3, 4, 5] (rest is list!)

# Swap
x, y = 10, 20
x, y = y, x

Tuple Methods

t = (3, 1, 4, 1, 5, 9, 2, 6, 5)

print(t.count(1))     # 2
print(t.index(5))     # 4
print(5 in t)         # True

Named Tuples

from collections import namedtuple

Point = namedtuple("Point", ["x", "y"])
p = Point(3, 4)
print(p.x)     # 3 — clear!
print(p.y)     # 4
print(p[0])    # 3 — still supports indexing

# From typing (Python 3.6+)
from typing import NamedTuple

class Point3D(NamedTuple):
    x: float
    y: float
    z: float = 0.0

Tuple vs List

Feature	Tuple	List
Mutability	Immutable	Mutable
Memory	Smaller (~33% less)	More
Hashable	Yes (dict key)	No
Methods	2 (count, index)	11+
Creation	Faster (~5x)	Slower

Why It Matters

Tuples are ideal for fixed data (coordinates, RGB colors, database records) and as dictionary keys.

Interview Questions

Q1: Why are tuples faster than lists?

A: Tuples are stored more compactly with no over-allocation. Constant tuples can be reused. Iteration is optimized in CPython.

Q2: Can a tuple contain mutable elements?

A: Yes! A tuple with a list inside can have that list modified: t = ([1,2], 3); t[0].append(4) — this works!

Practice Exercises

Create a named tuple for 2D coordinates and calculate distance.
Demonstrate the difference between == and is with tuples.
Compare memory usage of a tuple vs list with the same data.