Python Tuples Tutorial | Immutable Sequences and Operations

Python Tuples

Tuples are immutable, ordered sequences of elements. They are similar to lists but cannot be modified after creation.

What are Tuples?

Tuples are immutable sequences, typically used to store collections of heterogeneous data. They are defined using parentheses () and elements are separated by commas.

"Tuples are immutable lists."

Creating Tuples

# Empty tuple
empty_tuple = ()

# Tuple with elements
numbers = (1, 2, 3, 4, 5)
fruits = ("apple", "banana", "cherry")
mixed = (1, "hello", 3.14, True)

# Single element tuple (note the comma)
single = (42,)
not_tuple = (42)  # This is just 42

print(type(single))   # <class 'tuple'>
print(type(not_tuple)) # <class 'int'>

Tuple Operations

fruits = ("apple", "banana", "cherry")

# Indexing
print(fruits[0])   # 'apple'
print(fruits[-1])  # 'cherry'

# Slicing
print(fruits[1:3]) # ('banana', 'cherry')

# Concatenation
tuple1 = (1, 2, 3)
tuple2 = (4, 5, 6)
combined = tuple1 + tuple2
print(combined)  # (1, 2, 3, 4, 5, 6)

# Repetition
repeated = (1, 2) * 3
print(repeated)  # (1, 2, 1, 2, 1, 2)

# Membership
print("apple" in fruits)  # True
print(len(fruits))        # 3

Tuple Methods

Tuples have fewer methods than lists due to their immutability:

numbers = (1, 2, 3, 2, 4, 2)

# count() - Count occurrences
print(numbers.count(2))  # 3

# index() - Find first index
print(numbers.index(3))  # 2

# index() with start and end
print(numbers.index(2, 2, 5))  # 3

When to Use Tuples

Data Integrity: When you want to ensure data cannot be modified
Dictionary Keys: Tuples can be used as dictionary keys (lists cannot)
Function Returns: Returning multiple values from functions
Unpacking: Tuple unpacking is commonly used
Performance: Slightly faster than lists for iteration

Tuple Unpacking

# Basic unpacking
point = (3, 4)
x, y = point
print(x, y)  # 3 4

# Extended unpacking
numbers = (1, 2, 3, 4, 5)
first, *middle, last = numbers
print(first)   # 1
print(middle)  # [2, 3, 4]
print(last)    # 5

# Swapping values
a, b = 1, 2
a, b = b, a
print(a, b)  # 2 1

Named Tuples

Named tuples provide a way to create tuple subclasses with named fields:

from collections import namedtuple

# Define a named tuple
Point = namedtuple('Point', ['x', 'y'])
Person = namedtuple('Person', 'name age city')

# Create instances
p1 = Point(3, 4)
person1 = Person('Alice', 25, 'New York')

print(p1.x, p1.y)           # 3 4
print(person1.name)         # 'Alice'
print(person1.age)          # 25

# Convert to dictionary
print(person1._asdict())    # {'name': 'Alice', 'age': 25, 'city': 'New York'}

Tuples vs Lists

Aspect	Tuples	Lists
Mutability	Immutable	Mutable
Syntax	()	[]
Methods	Fewer methods	Many methods
Memory	Less memory	More memory
Performance	Faster	Slower
Use case	Fixed data	Changing data

Tuples are perfect when you need an immutable sequence of items. They provide data integrity and can be used as dictionary keys, making them valuable in many Python programs.