Resource expansion (embed related data) in Rest API - Mini Project: Build & Apply

Resource Expansion (Embed Related Data) in REST API

📖 Scenario: You are building a simple REST API for a bookstore. Each book has an author, and you want to send book data along with the author's details in one response. This is called resource expansion or embedding related data.

🎯 Goal: Build a REST API endpoint that returns a list of books with their embedded author information.

📋 What You'll Learn

Create a list of books with author IDs

Create a list of authors with their details

Write code to expand each book's author ID to the full author data

Return the expanded book list as JSON

💡 Why This Matters

🌍 Real World

Embedding related data in API responses helps clients get all needed information in one request, improving speed and user experience.

💼 Career

Understanding resource expansion is important for backend developers building efficient and user-friendly REST APIs.

1

Create the initial data structures

Create a list called books with these exact entries: {"id": 1, "title": "The Great Gatsby", "author_id": 101}, {"id": 2, "title": "1984", "author_id": 102}, and a list called authors with these exact entries: {"id": 101, "name": "F. Scott Fitzgerald"}, {"id": 102, "name": "George Orwell"}.

Rest API

# Create the books and authors lists with the exact entries
# Your code here

Need a hint?

Use lists of dictionaries exactly as shown. Each book has an author_id that matches an id in authors.

2

Create a helper dictionary for authors

Create a dictionary called author_map that maps each author's id to the full author dictionary from the authors list.

Rest API

books = [
    {"id": 1, "title": "The Great Gatsby", "author_id": 101},
    {"id": 2, "title": "1984", "author_id": 102}
]
authors = [
    {"id": 101, "name": "F. Scott Fitzgerald"},
    {"id": 102, "name": "George Orwell"}
]
# Create author_map dictionary here
# Your code here

Need a hint?

Use a dictionary comprehension to map author IDs to author data.

3

Expand books with embedded author data

Create a new list called expanded_books that contains each book dictionary plus a new key author with the full author dictionary from author_map. Use a for loop with variables book and expanded_books.

Rest API

books = [
    {"id": 1, "title": "The Great Gatsby", "author_id": 101},
    {"id": 2, "title": "1984", "author_id": 102}
]
authors = [
    {"id": 101, "name": "F. Scott Fitzgerald"},
    {"id": 102, "name": "George Orwell"}
]
author_map = {author["id"]: author for author in authors}
# Create expanded_books list with embedded author data
# Your code here

Need a hint?

Copy each book dictionary, add the author data, then add to expanded_books.

4

Print the expanded books list

Write a print statement to display the expanded_books list.

Rest API

books = [
    {"id": 1, "title": "The Great Gatsby", "author_id": 101},
    {"id": 2, "title": "1984", "author_id": 102}
]
authors = [
    {"id": 101, "name": "F. Scott Fitzgerald"},
    {"id": 102, "name": "George Orwell"}
]
author_map = {author["id"]: author for author in authors}

expanded_books = []
for book in books:
    expanded_book = book.copy()
    expanded_book["author"] = author_map[book["author_id"]]
    expanded_books.append(expanded_book)

# Print the expanded_books list
# Your code here

Need a hint?

Use print(expanded_books) to show the final list with embedded author data.