Chapter 7: Lists, Tuples, Dictionaries & Sets

7.1 Chapter Overview

In earlier chapters, learners used variables to store single values such as one name, one mark, or one course fee. However, real applications usually need to store many values together. Python provides collection data types such as lists, tuples, dictionaries, and sets to manage multiple values efficiently.

These data structures are useful in student registration systems, marks processing, course management, attendance tracking, inventory systems, and data analysis applications.

7.2 Chapter Objectives

• Understand the purpose of Python collection data types.
• Create and modify lists.
• Use tuples for fixed data.
• Create dictionaries using key-value pairs.
• Use sets to store unique values.
• Apply loops to process collections.
• Develop simple Python applications using collections.

Learning Outcomes

• Differentiate between lists, tuples, dictionaries, and sets.
• Store multiple values in Python collections.
• Access, update, add, and remove collection items.
• Use collections to build practical student and course management programs.

7.3 What are Collection Data Types?

Collection data types are used to store multiple values in a single variable. Each collection type has its own purpose, structure, and behavior.

7.4 Lists in Python

A list is used to store multiple values in one variable. Lists are ordered, changeable, and allow duplicate values.

Creating a List

courses = ["Python", "AI", "Data Science", "Cyber Security"]

print(courses)

Accessing List Items

List items are accessed using index numbers. Python indexing starts from 0.

courses = ["Python", "AI", "Data Science"]

print(courses[0])
print(courses[1])

7.5 Modifying Lists

Lists are changeable, so items can be updated, added, and removed.

Update an Item

courses = ["Python", "AI", "Data Science"]
courses[1] = "Machine Learning"

print(courses)

Add an Item

courses = ["Python", "AI"]
courses.append("Cyber Security")

print(courses)

Remove an Item

courses = ["Python", "AI", "Data Science"]
courses.remove("AI")

print(courses)

7.6 Looping Through Lists

A for loop can be used to process each item in a list.

students = ["Amin", "Mei Ling", "Ravi", "Siti"]

for student in students:
    print("Student Name:", student)

7.7 Tuples in Python

A tuple is similar to a list, but it cannot be changed after it is created. Tuples are useful for fixed data.

Creating a Tuple

weekdays = ("Monday", "Tuesday", "Wednesday", "Thursday", "Friday")

print(weekdays)

Accessing Tuple Items

weekdays = ("Monday", "Tuesday", "Wednesday")

print(weekdays[0])

7.8 When to Use Tuples

Tuples are best used when data should remain fixed and protected from accidental changes.

• Days of the week
• Months of the year
• Fixed course codes
• Permanent system settings
• Coordinates or fixed values

course_codes = ("CPP101", "AI201", "DS301")

for code in course_codes:
    print(code)

7.9 Dictionaries in Python

A dictionary stores data in key-value pairs. Each value is accessed using its key.

Creating a Dictionary

student = {
    "name": "Amin",
    "age": 20,
    "course": "Certified Python Programmer"
}

print(student)

Accessing Dictionary Values

student = {
    "name": "Amin",
    "age": 20,
    "course": "Python"
}

print(student["name"])
print(student["course"])

7.10 Updating Dictionaries

Update a Value

student = {
    "name": "Amin",
    "age": 20,
    "course": "Python"
}

student["course"] = "AI Application Development"

print(student)

Add a New Key-Value Pair

student = {
    "name": "Amin",
    "age": 20
}

student["email"] = "amin@example.com"

print(student)

Loop Through Dictionary

student = {
    "name": "Amin",
    "age": 20,
    "course": "Python"
}

for key, value in student.items():
    print(key, ":", value)

7.11 Sets in Python

A set is used to store unique values. Sets are unordered and do not allow duplicate items.

Creating a Set

skills = {"Python", "AI", "Data Science", "Python"}

print(skills)

The duplicate value "Python" will be stored only once.

Add Item to Set

skills = {"Python", "AI"}
skills.add("Cyber Security")

print(skills)

Remove Item from Set

skills = {"Python", "AI", "Data Science"}
skills.remove("AI")

print(skills)

7.12 Set Operations

Sets are useful when comparing groups of values.

Union

group_a = {"Python", "AI"}
group_b = {"Data Science", "AI"}

all_skills = group_a.union(group_b)

print(all_skills)

Intersection

group_a = {"Python", "AI"}
group_b = {"Data Science", "AI"}

common_skills = group_a.intersection(group_b)

print(common_skills)

7.13 Comparison of Python Collections

7.14 Practical Example: Student Record System

This example uses a dictionary to store student details and a list to store marks.

student = {
    "name": "Amin",
    "course": "Certified Python Programmer",
    "marks": [80, 75, 90]
}

total = 0

for mark in student["marks"]:
    total = total + mark

average = total / len(student["marks"])

print("Student Name:", student["name"])
print("Course:", student["course"])
print("Total Marks:", total)
print("Average Marks:", average)

7.15 Common Beginner Mistakes

7.16 Hands-On Practice

7.17 Final Assessment Quiz

Answer the following questions. Correct Answer = +1 Mark Wrong Answer = -0.5 Mark

Final Practical Assessment

Develop a Python program named student_collection_manager.py. The program must use a list for courses, a tuple for fixed centre details, a dictionary for one student profile, and a set for unique skills. Display all data clearly using loops where suitable.

7.18 Chapter Summary

In this chapter, learners studied Python collection data types: lists, tuples, dictionaries, and sets. Lists are flexible and changeable, tuples are fixed, dictionaries store key-value records, and sets store unique values.