Python Sample HTTP CRUD with FastAPI and Flask

In the world of Python web development, "CRUD" (Create, Read, Update, Delete) is the bread and butter of almost every application. But for beginners, the first hurdle isn't the logic—it's the tooling. Do you go with Flask, the reliable "micro-framework" that has been a industry staple for over a decade? Or do you reach for FastAPI, the high-performance newcomer that’s taking the dev world by storm? The biggest difference often comes down to how you run them. While FastAPI requires an external server like uvicorn to handle its asynchronous powers, Flask comes with its own "no-nonsense" built-in server for quick local development. fastapi_server.py from fastapi import FastAPI , HTTPException from pydantic import BaseModel from typing import Dict app = FastAPI () # Data Schema class User ( BaseModel ): name : str email : str # In-memory "Database" db : Dict [ int , User ] = {} @app.post ( " /users/{user_id} " ) def create_user ( user_id : int , user : User ): if user_id in db : raise HTTP