text: Title: local variable 'node' referenced before assignment
  Body: from chatterbot import ChatBot #import the chatbot
  from chatterbot.trainers import ChatterBotCorpusTrainer
  import os
  
  bot= ChatBot('Bot')
  trainer = ChatterBotCorpusTrainer(bot)
  
  corpus_path = 'C:/Users/p0v007a/Desktop/New folder/chatterbot-corpus-master/chatterbot_corpus/data/english/'
  
  for file in os.listdir(corpus_path):
      trainer.train(corpus_path + file)
  
  while True:
      message = input('You:')
      print(message)
      if message.strip() == 'Bye':
          print('ChatBot: Bye')
          break
      else:
          reply = bot.get_response(message)
          print('ChatBot:', reply)
  
  
  ![Unbound](https://user-images.githubusercontent.com/41320200/59960447-f6c46b00-94e5-11e9-8f05-1d8c72f11c48.PNG)
  ![chatterbot-corpus](https://user-images.githubusercontent.com/41320200/59960544-52432880-94e7-11e9-84c4-6b65ea0216a0.PNG)
  