How karthi-techdev/python-server-solid-principle works
Purpose and Entry Point
This is a small Python API service organized around product management. The application starts in app/main.py, which assembles the web application and exposes product routes from app/routes/products.py.
HTTP/API Boundary
app/routes/products.py is the inbound interface for product operations. It should receive request data, invoke the product service layer, and return schema-shaped responses. Request/response contracts are defined separately in app/schemas/products.py, keeping transport validation distinct from persistence entities.
Product Domain Model
app/models/product.py defines the product persistence/domain representation. It is the shared model boundary between database setup in app/db.py and repository operations in app/repositories/product_repository.py.
Service Layer
app/services/products_service.py contains product-use-case orchestration. This layer is the intended control-flow boundary between HTTP routes and persistence: routes delegate business operations to the service, while the service obtains or modifies data through the repository.
Persistence Layer
app/repositories/product_repository.py encapsulates product database access and shields the service layer from query/storage details. Database configuration, connection/session lifecycle, and ORM integration are centralized in app/db.py.
Primary Request Flow
For a product operation, control flows:
1. app/main.py initializes the application and route registration.
2. app/routes/products.py accepts and validates API input using app/schemas/products.py.
3. app/services/products_service.py applies product-level use-case logic.
4. app/repositories/product_repository.py reads or writes app/models/product.py through the database facilities in app/db.py.
5. The route serializes the resulting data into the API response schema.
Material Dependencies and Boundaries
The runtime dependencies are declared in requirements.txt. The codebase separates API transport (app/routes, app/schemas), application/business control flow (app/services), and persistence (app/repositories, app/models, app/db.py), allowing database implementation changes to remain behind the repository/database boundary.
Main entry points: products.py Product routes · product_repository.py Product repository · products_service.py Product service · db.py Database facilities
Components 8
API Transport
HTTP routing and transport contracts.
- Product routes · Receives product requests and returns API responses.
app/routes/products.py - Product schemas · Request validation and response serialization contracts.
app/schemas/products.py
Application
Product use-case orchestration.
- Product service · Orchestrates product use cases.
app/services/products_service.py
Persistence
Database access and product storage model.
- Product repository · Encapsulates product database queries and storage details.
app/repositories/product_repository.py - Product model · Shared product persistence and domain representation.
app/models/product.py - Database facilities · Centralizes database configuration, connections, and session lifecycle.
app/db.py
Other components
- Application entry · Builds the web application and registers product routes.
app/main.py - Runtime dependencies · Declares required Python runtime packages.
requirements.txt
Connections 8
- Application entry → Product routes: registers
- Product routes → Product schemas: validates and serializes
- Product routes → Product service: delegates operations
- Product service → Product repository: reads and writes
- Product repository → Product model: queries
- Product repository → Database facilities: uses sessions
- Database facilities → Product model: integrates ORM mapping
- Runtime dependencies → Application entry: provides runtime packages