RestAPI Python - Books API

A simple REST API for managing a collection of books, built with FastAPI and SQLAlchemy.

Overview

This project provides a RESTful API for performing CRUD (Create, Read, Update, Delete) operations on a books database. It demonstrates best practices for building modern Python APIs with FastAPI and SQLAlchemy ORM.

Features

• Get all books - Retrieve a list of all books in the database
• Add a book - Create a new book entry with title, author, description, and rating
• Update a book - Modify an existing book's details
• Delete a book - Remove a book from the database
• Input validation - Pydantic models ensure data integrity
• Database persistence - SQLite database for reliable data storage

Tech Stack

• Framework: FastAPI - Modern, fast web framework for building APIs
• ORM: SQLAlchemy - SQL toolkit and Object-Relational Mapping
• Validation: Pydantic - Data validation using Python type annotations
• Server: Uvicorn - ASGI web server
• Database: SQLite - Lightweight, file-based SQL database

Project Structure

RestApi_Python/
├── books.py           # FastAPI application and route handlers
├── models.py          # SQLAlchemy database models
├── database.py        # Database configuration and setup
├── test_books.py      # Comprehensive test suite
├── requirements.txt   # Python dependencies
├── pyproject.toml     # Project metadata and configuration
└── README.md          # This file

Installation

Prerequisites

• Python 3.13 or higher
• pip (Python package manager)

Setup

1. Clone or download the project:

cd RestApi_Python

2. Install dependencies:

pip install -r requirements.txt

Or using the project configuration:

pip install fastapi pydantic sqlalchemy uvicorn pytest httpx

Testing

The project includes a comprehensive test suite with 21 test cases covering all CRUD operations and edge cases.

Running Tests

Run the test suite using pytest:

pytest test_books.py -v

Or run with coverage report:

pytest test_books.py -v --cov=books

Test Coverage

The test suite is organized into 5 test classes:

TestCreateBook (10 tests)

• Valid book creation with all required fields
• Edge cases (zero rating, maximum rating of 100)
• Validation errors for missing fields
• Validation errors for invalid data (author exceeding 100 characters, ratings outside 0-100 range)
• Creating multiple books in sequence

TestReadBooks (2 tests)

• Retrieving books from an empty database
• Reading all books when data exists

TestUpdateBook (4 tests)

• Successfully updating a book's information
• Updating a non-existent book (404 error handling)
• Attempting to update with invalid data
• Updating specific fields while keeping others unchanged

TestDeleteBook (3 tests)

• Successfully deleting an existing book
• Deleting a non-existent book (404 error handling)
• Attempting to delete the same book multiple times

TestIntegration (2 tests)

• Complete CRUD workflow (Create → Read → Update → Delete)
• Multiple operations with multiple books

Test Results

All tests pass successfully:

21 passed, 1 warning in 1.94s

Usage

Running the API

Start the development server with Uvicorn:

uvicorn books:app --reload

The API will be available at http://localhost:8000

The interactive API documentation will be available at http://localhost:8000/docs

API Endpoints

Get All Books

GET /

Returns a list of all books in the database.

Example Response:

[
  {
    "id": 1,
    "title": "The Great Gatsby",
    "author": "F. Scott Fitzgerald",
    "description": "A classic American novel",
    "rating": 95
  }
]

Create a Book

POST /

Add a new book to the database.

Request Body:

{
  "title": "1984",
  "author": "George Orwell",
  "description": "A dystopian novel",
  "rating": 92
}

Validation Rules:

• title: Required, minimum 1 character
• author: Required, 1-100 characters
• description: Required, 1-100 characters
• rating: Required, integer between 0-100

Update a Book

PUT /{book_id}

Update an existing book's details.

Example:

PUT /1

Request Body: Same as POST

Delete a Book

DELETE /{book_id}

Remove a book from the database.

Example:

DELETE /1

Example Requests

Using cURL:

# Get all books
curl http://localhost:8000/

# Create a book
curl -X POST http://localhost:8000/ \
  -H "Content-Type: application/json" \
  -d '{"title":"Sample Book","author":"John Doe","description":"A good book","rating":85}'

# Update a book
curl -X PUT http://localhost:8000/1 \
  -H "Content-Type: application/json" \
  -d '{"title":"Updated Title","author":"John Doe","description":"A good book","rating":90}'

# Delete a book
curl -X DELETE http://localhost:8000/1

Database

The application uses SQLite with a file-based database (books.db). The database is automatically created on first run.

Books Table Schema

Column	Type	Details
id	Integer	Primary key, auto-incremented
title	String	Book title
author	String	Book author
description	String	Book description
rating	Integer	Book rating (0-100)

File Descriptions

• books.py: Main FastAPI application containing route handlers for all CRUD operations
• models.py: SQLAlchemy model definition for the Books table
• database.py: Database configuration, engine setup, and session management
• test_books.py: Comprehensive test suite with 21 test cases covering all endpoints and edge cases
• requirements.txt: List of Python package dependencies
• pyproject.toml: Project metadata and package configuration

Development

Adding Dependencies

To add a new dependency, update both requirements.txt and pyproject.toml:

pip install new-package
pip freeze > requirements.txt

Then update pyproject.toml with the new dependency and version.

Error Handling

The API includes error handling for common scenarios:

• 404 Not Found: Returned when trying to update or delete a book that doesn't exist
• 422 Unprocessable Entity: Returned when request data fails validation (handled automatically by Pydantic)

Future Enhancements

• User authentication and authorization
• Search and filtering functionality
• Pagination for large book collections
• Book categories and genres
• Rating and review system
• Database migrations with Alembic