pip install fastapi uvicorn

main.py

from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware

app = FastAPI()
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_credentials=True,
    allow_methods=["GET", "POST"],
    allow_headers=["*"],
)

@app.get("/")
def read_root():
	return {"message": "Hello World" }

Routers

routers/user.py

from fastapi import APIRouter

router = APIRouter()

@router.get("/")
def get_user():
    return {"message": "User Description" }

main.py

from fastapi import FastAPI
from routers import user

app = FastAPI()

@app.get("/")
def read_root():
    return {"message": "Hello World" }

app.include_router(user.router, prefix="/users", tags=["users"])