Implement a simple REST API using a framework like Flask or FastAPI, demonstrating basic CRUD operations.

from fastapi import FastAPI, HTTPException

app = FastAPI()
items = {}

@app.get("/items")
def get_items():
    return items

@app.post("/items/{id}")
def create_item(id: int, name: str):
    if id in items:
        raise HTTPException(400, "Exists")
    items[id] = {"name": name}
    return items[id]

@app.put("/items/{id}")
def update_item(id: int, name: str):
    if id not in items:
        raise HTTPException(404, "Not found")
    items[id]["name"] = name
    return items[id]

@app.delete("/items/{id}")
def delete_item(id: int):
    if id not in items:
        raise HTTPException(404, "Not found")
    del items[id]
    return {"msg": "Deleted"}