Simple Todo Application

Overview

This is a simple todo application API built with FastAPI and SQLite. It provides a RESTful API for managing todo items with the following features:

• Create, read, update, and delete todo items
• Filter todos by completion status
• Health check endpoint
• Validation and error handling
• CORS support
• Request logging

Technologies Used

• FastAPI: A modern, fast (high-performance) web framework for building APIs with Python
• SQLAlchemy: SQL toolkit and Object-Relational Mapping (ORM) for Python
• Pydantic: Data validation and settings management using Python type hints
• SQLite: Lightweight disk-based database
• Alembic: Database migration tool for SQLAlchemy
• Uvicorn: ASGI server for running the FastAPI application

Project Structure

.
├── app
│   ├── api
│   │   ├── endpoints
│   │   │   └── todos.py        # Todo API endpoints
│   │   ├── health.py           # Health check endpoint
│   │   └── routes.py           # API router setup
│   ├── core
│   │   ├── config.py           # Application configuration
│   │   ├── error_handlers.py   # Global error handlers
│   │   └── exceptions.py       # Custom exceptions
│   ├── db
│   │   ├── crud
│   │   │   ├── base.py         # Base CRUD operations
│   │   │   └── crud_todo.py    # Todo-specific CRUD operations
│   │   └── session.py          # Database session setup
│   ├── middleware
│   │   └── logging.py          # Request logging middleware
│   ├── models
│   │   ├── base.py             # Base SQLAlchemy model
│   │   └── todo.py             # Todo model definition
│   └── schemas
│       └── todo.py             # Pydantic schemas for Todo model
├── migrations
│   ├── env.py                  # Alembic environment configuration
│   ├── script.py.mako          # Alembic script template
│   └── versions
│       └── 20240101_initial_todo_table.py  # Initial database migration
├── alembic.ini                 # Alembic configuration
├── main.py                     # Application entry point
└── requirements.txt            # Project dependencies

API Endpoints

Health Check

• GET /health: Check the health of the application

Todo Endpoints

• GET /todos: List all todo items

  • Query parameters:
    • skip: Number of items to skip (default: 0)
    • limit: Maximum number of items to return (default: 100)
    • completed: Filter by completion status (optional)

• POST /todos: Create a new todo item

  • Request body:
    • title: Required string (1-100 characters)
    • description: Optional string (0-500 characters)
    • completed: Boolean (default: false)

• GET /todos/{todo_id}: Get a specific todo item by ID

• PUT /todos/{todo_id}: Update a todo item

  • Request body:
    • title: Optional string (1-100 characters)
    • description: Optional string (0-500 characters)
    • completed: Optional boolean

• DELETE /todos/{todo_id}: Delete a todo item

Setup and Installation

1. Clone the repository:

git clone <repository-url>
cd simple-todo-application

2. Install dependencies:

pip install -r requirements.txt

3. Run the application:

uvicorn main:app --host 0.0.0.0 --port 8000 --reload

4. Access the API documentation:
   • Swagger UI: http://localhost:8000/docs
   • ReDoc: http://localhost:8000/redoc

Database Migrations

The application uses Alembic for database migrations:

# Apply all migrations
alembic upgrade head

# Revert last migration
alembic downgrade -1

Configuration

The application can be configured using environment variables. Create a .env file in the project root with the following variables:

PROJECT_NAME=My Todo App
CORS_ORIGINS=["http://localhost:3000","https://example.com"]