Section Overview

In this section, you will learn about two important collection types in Python beyond lists and dictionaries: tuples and sets. Tuples are like lists but immutable, and sets store unique items without order.

By the end of this section, you should be able to:

• Understand what tuples are and how to create them
• Use tuples for fixed collections of data
• Understand what sets are and their properties
• Perform basic operations with sets

Lesson 1: Tuples – Immutable Sequences

Tuples are defined with parentheses () and cannot be changed after creation:

coordinates = (10, 20)
print(coordinates[0])  # Outputs: 10 

Because tuples are immutable, you cannot add or remove items:

# coordinates[0] = 15  # This would cause an error 

Tuples are useful for fixed data like RGB colors, geographic coordinates, or function returns.

Lesson 2: Sets – Collections of Unique Items

Sets are unordered collections of unique elements, created with curly braces {} or set():

fruits = {"apple", "banana", "orange"}
print(fruits)

Duplicates are automatically removed:

numbers = {1, 2, 2, 3}
print(numbers)  # Outputs: {1, 2, 3} 

Lesson 3: Basic Set Operations

You can add or remove items, and perform operations like union and intersection:

fruits.add("kiwi")
fruits.remove("banana")

a = {1, 2, 3}
b = {3, 4, 5}

print(a.union(b))         # {1, 2, 3, 4, 5} print(a.intersection(b))  # {3} print(a.difference(b))    # {1, 2} 

Quiz: Check Your Understanding

1. Can you change the items in a tuple after creation?
Answer: No, tuples are immutable.

2. How do sets handle duplicate values?
Answer: They automatically remove duplicates.

3. What does the .union() method do on sets?
Answer: Combines all unique elements from both sets.

4. What data type would you use for a fixed collection of values that should not change?
Answer: Tuple

Practice Exercise: Using Tuples and Sets

1. Create a tuple to represent a point (x, y) with values (5, 10)
2. Create a set of colors: "red", "green", "blue", "red"
3. Print the tuple and the set
4. Add "yellow" to the set and print it again

Starter code:

point = (5, 10)
colors = {"red", "green", "blue", "red"}

print("Point:", point)
print("Colors:", colors)

colors.add("yellow")
print("Updated colors:", colors)