text: from fastapi import FastAPI, HTTPException
  from fastapi.exceptions import RequestValidationError
  from starlette.exceptions import HTTPException as StarletteHTTPException
  from starlette.responses import PlainTextResponse
  
  app = FastAPI()
  
  
  @app.exception_handler(StarletteHTTPException)
  async def http_exception_handler(request, exc):
      return PlainTextResponse(str(exc.detail), status_code=exc.status_code)
  
  
  @app.exception_handler(RequestValidationError)
  async def validation_exception_handler(request, exc):
      return PlainTextResponse(str(exc), status_code=400)
  
  
  @app.get("/items/{item_id}")
  async def read_item(item_id: int):
      if item_id == 3:
          raise HTTPException(status_code=418, detail="Nope! I don't like 3.")
      return {"item_id": item_id}
  