input: Write a function to create a REST API in Python using Flask that allows deleting an item from a list. If the item is successfully deleted, return a message indicating so; otherwise, return a message indicating that the item was not found.
  
  
  from flask import Flask, request
  import json
  
  app = Flask(__name__)
  items = ["Apple", "Banana", "Orange"]
  
  @app.route('/items', methods=["GET"])
  def get_items():
      return json.dumps(items)
  
  @app.route('/items/<item>', methods=["DELETE"])
  def delete_item(item):
      if item in items:
          items.remove(item)
          message = "Item successfully deleted."
      else:
          message = "Item not found."
      return json.dumps({"message": message})
  
  
  assert delete_item("Banana")=="{\"message\": \"Item successfully deleted.\"}"
  assert delete_item("Grapes")=="{\"message\": \"Item not found.\"}"
  assert get_items()=="[\"Apple\", \"Orange\"]"
output: 
  def delete_item(item):
      if item in items:
          items.remove(item)
          message = "Item successfully deleted."
      else:
          message = "Item not found."
      return json.dumps({"message": message})
  