Lists and Tuples

Lists

Creating Lists

# Empty list
numbers = []
With values
fruits = ["apple", "banana", "cherry"]
mixed = [1, "hello", 3.14, True]

Accessing Elements

fruits = ["apple", "banana", "cherry"]
print(fruits[0])   # apple
print(fruits[-1])  # cherry

Modifying Lists

fruits = ["apple", "banana"]
fruits.append("cherry")      # Add to end
fruits.insert(1, "orange")   # Insert at index
fruits.remove("apple")       # Remove by value
popped = fruits.pop()        # Remove and return last

List Slicing

numbers = [0, 1, 2, 3, 4, 5]
print(numbers[1:4])    # [1, 2, 3]
print(numbers[:3])     # [0, 1, 2]
print(numbers[3:])     # [3, 4, 5]
print(numbers[::2])    # [0, 2, 4]

List Methods

numbers = [3, 1, 4, 1, 5]
print(len(numbers))      # 5
print(sorted(numbers))   # [1, 1, 3, 4, 5]
print(numbers.count(1))  # 2
print(numbers.index(4))  # 2

Tuples

Creating Tuples

# Empty tuple
point = ()
Single element (needs comma)
single = (5,)
Multiple elements
coordinates = (10, 20, 30)

Tuple Immutability

# This will cause an error!
point = (10, 20)
point[0] = 15  # TypeError!

Tuple Packing/Unpacking

# Packing
person = ("John", 30, "London")
Unpacking
name, age, city = person
print(name)   # John
print(age)    # 30

Summary

• Lists: mutable, dynamic arrays
• Tuples: immutable, fixed collections
• Both support indexing and slicing

Next Lesson

In the next lesson, you'll learn about dictionaries and sets.