Why dictionaries are used in Python - See It in Action

Why dictionaries are used

📖 Scenario: Imagine you run a small library. You want to keep track of books and their authors quickly. You need a way to find the author of any book easily.

🎯 Goal: You will create a dictionary to store book titles and their authors. Then, you will look up authors by book titles to see why dictionaries are useful.

📋 What You'll Learn

Create a dictionary called library with exact book-author pairs

Create a variable called book_to_find with a specific book title

Use dictionary access to get the author of book_to_find

Print the author name

💡 Why This Matters

🌍 Real World

Libraries, stores, and many apps use dictionaries to quickly find information by a unique key like a book title or product code.

💼 Career

Knowing how to use dictionaries helps you work with data efficiently, a key skill in programming jobs like web development, data analysis, and software engineering.

1

Create the library dictionary

Create a dictionary called library with these exact entries: 'The Hobbit': 'J.R.R. Tolkien', '1984': 'George Orwell', 'Pride and Prejudice': 'Jane Austen'

Python

# Create the library dictionary with book titles and authors
# Your code here

Need a hint?

Use curly braces {} to create a dictionary. Each entry has a book title as key and author as value.

2

Choose a book to find

Create a variable called book_to_find and set it to the string '1984'

Python

library = {'The Hobbit': 'J.R.R. Tolkien', '1984': 'George Orwell', 'Pride and Prejudice': 'Jane Austen'}
# Create the variable book_to_find with the value '1984'
# Your code here

Need a hint?

Use = to assign the string '1984' to the variable book_to_find.

3

Find the author using the dictionary

Create a variable called author and set it to the value from library for the key book_to_find

Python

library = {'The Hobbit': 'J.R.R. Tolkien', '1984': 'George Orwell', 'Pride and Prejudice': 'Jane Austen'}
book_to_find = '1984'
# Get the author from the library dictionary using book_to_find
# Your code here

Need a hint?

Use square brackets [] with the dictionary name and key variable to get the value.

4

Print the author

Write a print statement to display the value of the variable author

Python

library = {'The Hobbit': 'J.R.R. Tolkien', '1984': 'George Orwell', 'Pride and Prejudice': 'Jane Austen'}
book_to_find = '1984'
author = library[book_to_find]
# Print the author
# Your code here

Need a hint?

Use print(author) to show the author's name on the screen.