Python Development Guide
Python 3.13+ 개발을 위한 간결한 가이드.
Quick Reference
| 용도 | 도구 | 특징 | |
|---|
| Web Framework | FastAPI | 빠름, 타입 힌트, OpenAPI | |
| Web Framework | Django | 풀스택, 관리자, ORM | |
| Validation | Pydantic | 데이터 검증 | |
| Testing | pytest | 유연한 테스팅 | |
Project Setup
bash
# uv (권장)
uv init project && cd project
uv add fastapi uvicorn pydantic sqlalchemy
# poetry
poetry new project && cd project
poetry add fastapi uvicorn pydantic
# pip
python -m venv .venv && source .venv/bin/activate
pip install fastapi uvicorn pydantic
FastAPI Patterns
Basic API
python
from fastapi import FastAPI, Depends, HTTPException
from pydantic import BaseModel
app = FastAPI()
class UserCreate(BaseModel):
name: str
email: str
class UserResponse(BaseModel):
id: int
name: str
email: str
model_config = {"from_attributes": True}
@app.post("/users", response_model=UserResponse)
async def create_user(data: UserCreate):
user = await UserService.create(data)
return user
@app.get("/users/{user_id}")
async def get_user(user_id: int):
user = await UserService.get(user_id)
if not user:
raise HTTPException(status_code=404, detail="User not found")
return user
Dependency Injection
python
from fastapi import Depends
from sqlalchemy.ext.asyncio import AsyncSession
async def get_db() -> AsyncGenerator[AsyncSession, None]:
async with async_session() as session:
yield session
@app.get("/users")
async def list_users(db: AsyncSession = Depends(get_db)):
return await UserRepository(db).list_all()
Authentication
python
from fastapi import Depends, HTTPException, status
from fastapi.security import HTTPBearer
security = HTTPBearer()
async def get_current_user(token: str = Depends(security)):
user = await verify_token(token.credentials)
if not user:
raise HTTPException(status_code=401, detail="Invalid token")
return user
@app.get("/me")
async def get_me(user: User = Depends(get_current_user)):
return user
Pydantic v2 Patterns
python
from pydantic import BaseModel, Field, field_validator
class User(BaseModel):
id: int
name: str = Field(min_length=2, max_length=50)
email: str
age: int | None = None
model_config = {"from_attributes": True, "str_strip_whitespace": True}
@field_validator("email")
@classmethod
def validate_email(cls, v: str) -> str:
if "@" not in v:
raise ValueError("Invalid email")
return v.lower()
# Usage
user = User.model_validate(orm_object)
user_dict = user.model_dump()
user_json = user.model_dump_json()
SQLAlchemy 2.0 Async
python
from sqlalchemy.ext.asyncio import AsyncSession, create_async_engine
from sqlalchemy.orm import DeclarativeBase, Mapped, mapped_column
class Base(DeclarativeBase):
pass
class User(Base):
__tablename__ = "users"
id: Mapped[int] = mapped_column(primary_key=True)
name: Mapped[str] = mapped_column(String(50))
email: Mapped[str] = mapped_column(String(100), unique=True)
# Repository
class UserRepository:
def __init__(self, session: AsyncSession):
self.session = session
async def get(self, user_id: int) -> User | None:
return await self.session.get(User, user_id)
async def create(self, data: UserCreate) -> User:
user = User(**data.model_dump())
self.session.add(user)
await self.session.commit()
return user
pytest Patterns
python
import pytest
from httpx import AsyncClient
@pytest.fixture
async def client():
async with AsyncClient(app=app, base_url="http://test") as ac:
yield ac
@pytest.mark.asyncio
async def test_create_user(client: AsyncClient):
response = await client.post("/users", json={
"name": "John",
"email": "john@example.com"
})
assert response.status_code == 200
assert response.json()["name"] == "John"
# Parametrize
@pytest.mark.parametrize("email,expected", [
("valid@email.com", True),
("invalid", False),
("", False),
])
def test_validate_email(email, expected):
result = validate_email(email)
assert result == expected
Project Structure
project/
├── src/
│ └── project/
│ ├── __init__.py
│ ├── main.py
│ ├── api/
│ │ └── routes/
│ ├── core/
│ │ └── config.py
│ ├── models/
│ ├── schemas/
│ └── services/
├── tests/
├── pyproject.toml
└── README.md
Best Practices
- Type Hints: 모든 함수에 타입 힌트 사용
- Async: I/O 작업에 async/await 사용
- Pydantic: 입출력 검증에 Pydantic 모델 사용
- Dependency Injection: FastAPI Depends로 의존성 주입
- 환경변수: pydantic-settings로 설정 관리
Last Updated: 2026-01-21 Version: 2.0.0