Fastapi Tutorial Pdf · Limited Time

@app.get("/items/") async def list_items(skip: int = 0, limit: int = 10): return "skip": skip, "limit": limit

If you want a pre-made guide, these are the most authoritative sources:

To follow this tutorial, you need Python 3.8 or higher installed on your system. Step 1: Create a Virtual Environment

Very high performance, on par with NodeJS and Go (thanks to Starlette and Pydantic) 1. fastapi tutorial pdf

Create a project directory and install FastAPI and uvicorn (a lightning-fast ASGI server) 1:

Mastering FastAPI: The Ultimate Guide to Building High-Performance APIs

from fastapi import Depends, HTTPException from sqlalchemy.orm import Session from .database import engine, Base, get_db from .models import DBProduct Base.metadata.create_all(bind=engine) @app.post("/products/") def add_product(name: str, price: float, db: Session = Depends(get_db)): product = DBProduct(name=name, price=price) db.add(product) db.commit() db.refresh(product) return product Use code with caution. 7. Dependency Injection System Query Parameters and Path Validation Nothing beats learning

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

Nothing beats learning by doing. These repositories provide excellent, runnable code examples:

Declare function arguments that aren't part of the path to automatically handle query strings (e.g., 3. Request Body & Pydantic Models Getting Started with Python and FastAPI - PyImageSearch Dependency Injection System

To get started, you need the FastAPI library and an ASGI server like to run your application. pip install "fastapi[standard]" Use code with caution. Copied to clipboard Step 2: Your First "Hello World" API Create a file named and add the following code to define a basic endpoint: = FastAPI()

from fastapi import FastAPI, HTTPException, status from pydantic import BaseModel from typing import List, Dict app = FastAPI() class Post(BaseModel): id: int title: str content: str # Simulated Database db_posts: Dict[int, Post] = {} @app.post("/posts/", response_model=Post, status_code=status.HTTP_201_CREATED) def create_post(post: Post): if post.id in db_posts: raise HTTPException(status_code=400, detail="Post ID already exists") db_posts[post.id] = post return post @app.get("/posts/", response_model=List[Post]) def get_all_posts(): return list(db_posts.values()) @app.get("/posts/post_id", response_model=Post) def get_post(post_id: int): if post_id not in db_posts: raise HTTPException(status_code=404, detail="Post not found") return db_posts[post_id] @app.put("/posts/post_id", response_model=Post) def update_post(post_id: int, updated_post: Post): if post_id not in db_posts: raise HTTPException(status_code=404, detail="Post not found") db_posts[post_id] = updated_post return updated_post @app.delete("/posts/post_id", status_code=status.HTTP_204_NO_CONTENT) def delete_post(post_id: int): if post_id not in db_posts: raise HTTPException(status_code=404, detail="Post not found") del db_posts[post_id] return None Use code with caution. 8. Dependency Injection System