Lists and Tuples

Creating, indexing, slicing, and iterating over ordered collections.

Lists

A list is an ordered, mutable collection that can hold items of any type:

fruits = ["apple", "banana", "cherry"]
numbers = [10, 20, 30, 40]
mixed  = ["Alice", 25, True, 3.14]

Accessing and Modifying

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

List Methods

fruits.append("date")      # add to end
fruits.insert(1, "avocado") # insert at index
fruits.remove("cherry")    # remove by value
popped = fruits.pop()        # remove and return last item
fruits.sort()                # sort in place
fruits.reverse()             # reverse in place
print(len(fruits))          # number of items

Tuples

Tuples are like lists but immutable — once created they cannot be changed. They use parentheses:

point = (3, 7)
rgb   = (255, 128, 0)
print(point[0])   # 3
x, y = point       # unpacking

Iterating Over a List

scores = [88, 72, 95, 60]
for score in scores:
    print(f"Score: {score}")

# With index
for i, score in enumerate(scores):
    print(f"{i+1}. {score}")