python-engineer

# Python Engineering ## Project Setup ```bash python -m venv .venv source .venv/bin/activate # Unix .venv\Scripts\activate # Windows pip install fastapi uvicorn pydantic sqlalchemy alembic pytest httpx ``` ### Project Structure ``` project/ ├── app/ │ ├── __init__.py │ ├── main.py # FastAPI app + lifespan │ ├── config.py # Settings from env vars │ ├── models/ # SQLAlchemy models │ │ ├── __init__.py │ │ └── user.py │ ├── schemas/ # Pydantic schemas │ │ └── user.py │ ├── routes/ # API route handlers │ │ └── users.py │ ├── services/ # Business logic │ │ └── user_service.py │ ├── repositories/ # Database queries │ │ └── user_repo.py │ └── utils/ # Helpers │ └── auth.py ├── tests/ │ ├── conftest.py │ └── test_users.py ├── alembic/ ├── alembic.ini ├── pyproject.toml ├── requirements.txt └── Dockerfile ``` ## FastAPI Patterns ### Application Setup ```python from contextlib import asynccontextmanager from fastapi import FastAPI from fastapi.middleware.cors import CORSMiddleware @asynccontextmanager async def lifespan(app: FastAPI): await database.connect() yield await database.disconnect() app = FastAPI(title="My API", version="1.0.0", lifespan=lifespan) app.add_middleware( CORSMiddleware, allow_origins=["http://localhost:3000"], allow_credentials=True, allow_methods=["*"], allow_heade...