To-Do List API using FastAPI

Project Overview

This project is a simple REST API built using FastAPI that allows users to create and manage to-do lists.

The application demonstrates the basics of FastAPI, REST API development, object-oriented programming (OOP), and the SOLID design principles (Single Responsibility Principle and Open/Closed Principle).

The project stores data in memory using Python data structures, so no database is required.

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Features

• Create a new to-do list
• View all to-do lists
• Update a to-do list
• Delete a to-do list
• Search for a to-do list by keyword

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Technologies Used

• Python 3
• FastAPI
• Pydantic
• Uvicorn

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Project Structure

todo_project/
│
├── main.py          # FastAPI routes
├── models.py        # Pydantic models and business logic
├── requirements.txt
└── README.md

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API Endpoints

Method	Endpoint	Description
GET	/lists	Retrieve all to-do lists
POST	/lists	Create a new to-do list
PUT	/lists/{list_id}	Update a to-do list
DELETE	/lists/{list_id}	Delete a to-do list
GET	/lists/search/{keyword}	Search to-do lists by name

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How to Run the Project

1. Clone the repository

git clone <repository-url>

2. Navigate to the project folder

cd todo_project

3. Install the dependencies

pip install -r requirements.txt

4. Start the FastAPI server

uvicorn main:app --reload

If port 8000 is already in use:

uvicorn main:app --reload --port 8001

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Swagger API Documentation

After starting the server, open the following URL in your browser:

http://127.0.0.1:8000/docs

or

http://127.0.0.1:8001/docs

Swagger UI provides interactive API documentation where all endpoints can be tested directly.

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SOLID Principles Used

Single Responsibility Principle (SRP)

• main.py is responsible for handling HTTP requests and responses.
• models.py contains the Pydantic models and the application's business logic.
• Each class has a single, well-defined responsibility.

Open/Closed Principle (OCP)

The project uses inheritance to extend functionality.

• BaseTodoService provides the core CRUD operations.
• TodoService extends BaseTodoService by adding the search functionality.

This allows new features to be added without modifying the existing base class, making the code open for extension but closed for modification.

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Future Enhancements

• Add support for to-do items within each list.
• Integrate a SQL database such as SQLite or PostgreSQL.
• Add user authentication and authorization.
• Implement persistent data storage.
• Add automated unit tests using Pytest.
• Containerize the application using Docker.

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Learning Outcomes

This project demonstrates:

• FastAPI fundamentals
• REST API development
• Pydantic data validation
• Object-Oriented Programming (OOP)
• Service layer design
• Single Responsibility Principle (SRP)
• Open/Closed Principle (OCP)
• CRUD operations
• API testing with Swagger UI