old_contents: from flask import Flask
  from config import config
  
  def create_app(config_name):
      app = Flask(__name__)
  
      app.config_from_object(config[config_name])
  
      return app
  
new_contents: from flask import Flask
  from config import config
  
  def create_app(config_name):
      app = Flask(__name__)
  
      app.config.from_object(config[config_name])
  
      return app
  
subject: load app configuration