input: from typing import List
  
  import flask
  from flask import Flask, request, jsonify
  import json
  
  app = Flask(name)
  
  @app.route('/countries', methods=['GET'])
  def get_countries():
      with open('data.json', 'r') as f:
          countries = json.load(f)
      return jsonify(countries)
  
  if name == 'main':
      app.run()
  
  """
  You are tasked with creating a basic REST API using Python and Flask to list all the countries in the world. The API should read the list of countries from a JSON file and return it as a response to a GET request. The API should be available at the endpoint '/countries'.
  
  Example:
  If the 'data.json' file contains:
  [
      {"name": "Afghanistan", "code": "AF"},
      {"name": "Albania", "code": "AL"},
      {"name": "Algeria", "code": "DZ"}
  ]
  Then a GET request to '/countries' should return:
  [
      {"name": "Afghanistan", "code": "AF"},
      {"name": "Albania", "code": "AL"},
      {"name": "Algeria", "code": "DZ"}
  ]
  """
output:     
      app.run(debug=True)
  