Codexpal - Learn Programming Interactively

Lesson Content

Tuples and Sets: More Data Structures

Python has several built-in data structures. Let's explore tuples and sets, which have different use cases than lists.

Tuples

Tuples are ordered, immutable collections. Once created, they cannot be changed.

# Creating tuples
coordinates = (10, 20)
point = 10, 20  # Parentheses optional

# Single item tuple (needs comma)
single = (5,)  # Not (5) which is just a number

# Accessing items (like lists)
print(coordinates[0])  # 10
print(coordinates[1])  # 20

# Tuples are immutable (cannot change)
# coordinates[0] = 5  # Error!

Tuple Operations

tuple1 = (1, 2, 3)
tuple2 = (4, 5)

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

# Repetition
repeated = tuple1 * 2  # (1, 2, 3, 1, 2, 3)

# Unpacking
x, y = (10, 20)  # x = 10, y = 20

# Length
print(len(tuple1))  # 3

When to Use Tuples

✅ Coordinates (x, y)
✅ RGB colors (255, 0, 0)
✅ Database records
✅ When you want to prevent accidental changes

Sets

Sets are unordered collections of unique items. No duplicates allowed!

# Creating sets
fruits = {"apple", "banana", "orange"}
numbers = {1, 2, 3, 4, 5}

# Empty set (not {})
empty = set()  # {} creates a dictionary!

# Sets automatically remove duplicates
unique = {1, 2, 2, 3, 3, 3}  # {1, 2, 3}

Set Operations

set1 = {1, 2, 3, 4}
set2 = {3, 4, 5, 6}

# Add item
set1.add(5)  # {1, 2, 3, 4, 5}

# Remove item
set1.remove(5)  # {1, 2, 3, 4}
set1.discard(10)  # No error if not found

# Union (all items from both)
union = set1 | set2  # {1, 2, 3, 4, 5, 6}
union = set1.union(set2)

# Intersection (common items)
intersection = set1 & set2  # {3, 4}
intersection = set1.intersection(set2)

# Difference (items in set1 but not set2)
diff = set1 - set2  # {1, 2}
diff = set1.difference(set2)

Set Methods

numbers = {1, 2, 3}

# Check membership (very fast!)
print(2 in numbers)  # True

# Length
print(len(numbers))  # 3

# Clear all items
numbers.clear()  # set()

When to Use Sets

✅ Remove duplicates from a list
✅ Fast membership testing
✅ Mathematical set operations
✅ Tracking unique items

Converting Between Types

# List to tuple
my_list = [1, 2, 3]
my_tuple = tuple(my_list)  # (1, 2, 3)

# List to set (removes duplicates)
my_list = [1, 2, 2, 3, 3]
my_set = set(my_list)  # {1, 2, 3}

# Set to list
my_list = list(my_set)  # [1, 2, 3]

Example Code

Practice using tuples and sets.

# Create a tuple for coordinates
point = (10, 20)

# Unpack the tuple
x, y = point
print(f"X: {x}, Y: {y}")

# Create a set of unique numbers
numbers = {1, 2, 3, 4, 5}

# Add a number
numbers.add(6)
print(f"Numbers: {numbers}")

# Check if 3 is in the set
print(f"3 in set: {3 in numbers}")

Expected Output:

X: 10, Y: 20
Numbers: {1, 2, 3, 4, 5, 6}
3 in set: True

Study Tips

•Read the theory content thoroughly before practicing
•Review the example code to understand key concepts
•Proceed to the Practice tab when you're ready to code