Directory structure for building a stock system using FastAPI

This structure separates concerns, making it easier to manage as the project scales.

stock-system/
│
├── app/
│   ├── __init__.py
│   ├── main.py                     # Entry point of the FastAPI app
│   ├── api/                        # API related code (routers)
│   │   ├── __init__.py
│   │   ├── products.py              # Routes related to products
│   │   ├── inventory.py             # Routes related to inventory management
│   │   ├── sales.py                 # Routes related to sales and orders
│   │   └── users.py                 # Routes related to user management
│   │
│   ├── core/                       # Core settings and configurations
│   │   ├── __init__.py
│   │   ├── config.py                # Configuration settings (DB, API keys, etc.)
│   │   └── security.py              # Authentication, Authorization, and Security utilities
│   │
│   ├── crud/                       # CRUD operations for database interactions
│   │   ├── __init__.py
│   │   ├── crud_product.py          # CRUD operations related to products
│   │   ├── crud_inventory.py        # CRUD operations related to inventory
│   │   ├── crud_sales.py            # CRUD operations related to sales
│   │   └── crud_user.py             # CRUD operations related to users
│   │
│   ├── db/                         # Database-related modules
│   │   ├── __init__.py
│   │   ├── base.py                  # SQLAlchemy base for models
│   │   ├── session.py               # Database session creation
│   │   └── models/                  # SQLAlchemy models
│   │       ├── __init__.py
│   │       ├── product.py           # Product model
│   │       ├── inventory.py         # Inventory model
│   │       ├── sales.py             # Sales/Orders model
│   │       └── user.py              # User model
│   │
│   ├── schemas/                    # Pydantic schemas for request/response models
│   │   ├── __init__.py
│   │   ├── product.py               # Product-related schemas
│   │   ├── inventory.py             # Inventory-related schemas
│   │   ├── sales.py                 # Sales-related schemas
│   │   └── user.py                  # User-related schemas
│   │
│   ├── services/                   # Additional business logic/services
│   │   ├── __init__.py
│   │   ├── product_service.py       # Logic related to products
│   │   ├── inventory_service.py     # Logic related to inventory
│   │   ├── sales_service.py         # Logic related to sales
│   │   └── user_service.py          # Logic related to users
│   │
│   └── utils/                      # Utility functions/helpers
│       ├── __init__.py
│       ├── dependencies.py          # Common dependencies for routes
│       └── helpers.py               # Miscellaneous helper functions
│
├── tests/                          # Test cases
│   ├── __init__.py
│   ├── test_products.py             # Tests related to products
│   ├── test_inventory.py            # Tests related to inventory
│   ├── test_sales.py                # Tests related to sales/orders
│   └── test_users.py                # Tests related to users
│
├── alembic/                        # Database migrations using Alembic (if needed)
│   ├── versions/                    # Directory for migration scripts
│   └── env.py                       # Alembic environment configuration
│
├── Dockerfile                      # Dockerfile for containerizing the application
├── .env                            # Environment variables file (for secrets and config)
├── .gitignore                      # Files and directories to ignore in git
├── pyproject.toml                   # Dependencies and project metadata (or requirements.txt)
├── README.md                       # Documentation of the project
└── uvicorn_config.py               # Configuration for running the FastAPI app with Uvicorn

Key Directories and Files:

• app/main.py: The entry point for the FastAPI application. It initiates the app, includes routers, and other configurations.
• api/: Contains route definitions for various aspects of the stock system (products, inventory, sales, users).
• db/: Includes SQLAlchemy models, the database session setup, and related files.
• crud/: Handles the interaction between the database and the API through CRUD operations.
• schemas/: Defines Pydantic models used for validation and serialization of request and response data.
• services/: Contains the business logic for various features of the system.
• tests/: Contains unit tests and integration tests to ensure functionality.
• alembic/: If you're using Alembic for database migrations, this is where the migration files will go.

This structure is flexible and scalable for a stock system, promoting separation of concerns, easier testing, and maintenance.