Fastapi Tutorial Pdf |work| -

from sqlalchemy import create_backend, create_engine from sqlalchemy.ext.declarative import declarative_base from sqlalchemy.orm import sessionmaker SQLALCHEMY_DATABASE_URL = "sqlite:///./sql_app.db" engine = create_engine( SQLALCHEMY_DATABASE_URL, connect_args="check_same_thread": False ) SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine) Base = declarative_base() # Dependency to get db session def get_db(): db = SessionLocal() try: yield db finally: db.close() Use code with caution. models.py Defines the SQLAlchemy database tables.

FROM python:3.10-slim WORKDIR /code COPY ./requirements.txt /code/requirements.txt RUN pip install --no-cache-dir --upgrade -r /code/requirements.txt COPY ./app /code/app CMD ["uvicorn", "app.main:app", "--host", "0.0.0.0", "--port", "80"] Use code with caution. Build and Run the Container

from sqlalchemy import create_engine, Column, Integer, String from sqlalchemy.ext.declarative import declarative_base from sqlalchemy.orm import sessionmaker from fastapi import FastAPI, Depends from sqlalchemy.orm import Session DATABASE_URL = "sqlite:///./test.db" engine = create_engine(DATABASE_URL, connect_args="check_same_thread": False) SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine) Base = declarative_base() # Database Model class DBUser(Base): __tablename__ = "users" id = Column(Integer, primary_key=True, index=True) name = Column(String, index=True) Base.metadata.create_all(bind=engine) # Dependency to yield database sessions def get_db(): db = SessionLocal() try: yield db finally: db.close() app = FastAPI() @app.post("/db-users/") def add_db_user(name: str, db: Session = Depends(get_db)): new_user = DBUser(name=name) db.add(new_user) db.commit() db.refresh(new_user) return new_user Use code with caution. 7. Asynchronous Programming in FastAPI

: Often described as beginner-friendly, with many developers able to grasp the basics within a week. Finding Tutorial PDFs fastapi tutorial pdf

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If a client sends a request missing the email field or provides a string for age , FastAPI will automatically block the request and return a detailed 422 Unprocessable Entity error. 4. Query Parameters and Path Validation

--reload : Automatically restarts the server when code changes are detected (use only for development). Build and Run the Container from sqlalchemy import

Even though the application receives a password, the response_model=UserOut ensures the password is omitted from the JSON response sent back to the user. Handling HTTP Exceptions

from datetime import datetime, timedelta from fastapi import Depends, FastAPI, HTTPException, status from fastapi.security import OAuth2PasswordBearer, OAuth2PasswordRequestForm from jose import JWTError, jwt from passlib.context import CryptContext # Configuration configurations SECRET_KEY = "SUPER_SECRET_SIGNING_KEY" ALGORITHM = "HS256" ACCESS_TOKEN_EXPIRE_MINUTES = 30 pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto") oauth2_scheme = OAuth2PasswordBearer(tokenUrl="token") def verify_password(plain_password, hashed_password): return pwd_context.verify(plain_password, hashed_password) def get_password_hash(password): return pwd_context.hash(password) def create_access_token(data: dict): to_encode = data.copy() expire = datetime.utcnow() + timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES) to_encode.update("exp": expire) return jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM) app = FastAPI() @app.post("/token") async def login(form_data: OAuth2PasswordRequestForm = Depends()): # Example placeholder credential validation if form_data.username != "admin" or form_data.password != "secret": raise HTTPException(status_code=400, detail="Incorrect username or password") access_token = create_access_token(data="sub": form_data.username) return "access_token": access_token, "token_type": "bearer" @app.get("/secure-data") async def get_secure_data(token: str = Depends(oauth2_scheme)): try: payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM]) username: str = payload.get("sub") if username is None: raise HTTPException(status_code=401, detail="Invalid token") except JWTError: raise HTTPException(status_code=401, detail="Could not validate credentials") return "protected_info": f"Hello username, this data is protected by JWT tokens." Use code with caution. 9. Advanced Concepts Middlewares

📍 When reading a PDF, keep a terminal open. FastAPI is best learned by running uvicorn main:app --reload and watching the docs update in real-time. Explain how to dockerize a FastAPI app for your guide? Finding Tutorial PDFs This public link is valid

The framework uses Python type hints to validate data, catching errors early.

Should I add a comprehensive section on like SQLModel or SQLAlchemy?

If a user visits /users/abc , FastAPI immediately returns a 422 Unprocessable Entity error, explaining that user_id must be an integer. Query Parameters

FastAPI Tutorial PDF – Clear, Concise, but Could Be Deeper