input: from flask import Flask, request
  import json
  
  def create_delete_item_api():
      """
      Create a REST API in Python using Flask that allows deleting an item from a predefined list of items.
  
      Example:
      >>> app = create_delete_item_api()
      >>> items = ["Apple", "Banana", "Orange"]
      >>> app.test_client().delete('/items/Banana')
      >>> print(json.dumps(items))
      '["Apple", "Orange"]'
      """
      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})
      
      return app
output:     if __name__ == "__main__":
          app.run(debug=True)