Why project structure matters at scale in FastAPI - See It in Action

Why project structure matters at scale

📖 Scenario: You are building a simple FastAPI application to manage a small library of books. As the app grows, organizing your code well will help keep it easy to understand and maintain.

🎯 Goal: Build a FastAPI app with a clear project structure by creating a data list, a configuration variable, a route to get books, and finally include the router in the main app.

📋 What You'll Learn

Create a list of books with exact titles and authors

Add a configuration variable for the API prefix

Create a FastAPI router with a GET endpoint to return the books list

Include the router in the main FastAPI app with the prefix

💡 Why This Matters

🌍 Real World

Organizing FastAPI projects clearly helps teams work together and makes adding features easier.

💼 Career

Understanding project structure is key for backend developers building scalable APIs with FastAPI.

1

Create the initial data list

Create a list called books with these exact dictionaries: {'title': '1984', 'author': 'George Orwell'}, {'title': 'Brave New World', 'author': 'Aldous Huxley'}, and {'title': 'Fahrenheit 451', 'author': 'Ray Bradbury'}.

FastAPI

# Create the books list with exact entries
# Your code here

Need a hint?

Use a list of dictionaries with the exact keys and values given.

2

Add API prefix configuration

Create a string variable called API_PREFIX and set it to "/library".

FastAPI

books = [
    {'title': '1984', 'author': 'George Orwell'},
    {'title': 'Brave New World', 'author': 'Aldous Huxley'},
    {'title': 'Fahrenheit 451', 'author': 'Ray Bradbury'}
]
# Create API_PREFIX variable
# Your code here

Need a hint?

Just assign the string "/library" to API_PREFIX.

3

Create a FastAPI router with GET endpoint

Import APIRouter from fastapi. Create a router called router. Add a GET endpoint /books to router that returns the books list.

FastAPI

books = [
    {'title': '1984', 'author': 'George Orwell'},
    {'title': 'Brave New World', 'author': 'Aldous Huxley'},
    {'title': 'Fahrenheit 451', 'author': 'Ray Bradbury'}
]

API_PREFIX = "/library"

# Import APIRouter and create router
# Add GET /books endpoint returning books
# Your code here

Need a hint?

Use @router.get("/books") decorator and an async function returning books.

4

Include the router in the main FastAPI app

Import FastAPI from fastapi. Create an app called app. Include the router in app using API_PREFIX as the prefix.

FastAPI

from fastapi import APIRouter

books = [
    {'title': '1984', 'author': 'George Orwell'},
    {'title': 'Brave New World', 'author': 'Aldous Huxley'},
    {'title': 'Fahrenheit 451', 'author': 'Ray Bradbury'}
]

API_PREFIX = "/library"

router = APIRouter()

@router.get("/books")
async def get_books():
    return books

# Import FastAPI, create app, and include router with prefix
# Your code here

Need a hint?

Use app.include_router(router, prefix=API_PREFIX) to add the router.