将上述代码整合成一个完整代码

以下是整合后的完整代码：

import torch
from transformers import GPT2Tokenizer, GPT2LMHeadModel

class ChitChat:
    def __init__(self):
        self.tokenizer = GPT2Tokenizer.from_pretrained('microsoft/DialoGPT-medium')
        self.model = GPT2LMHeadModel.from_pretrained('microsoft/DialoGPT-medium')
        self.device = torch.device('cuda' if torch.cuda.is_available() else 'cpu')
        self.model.to(self.device)
        self.model.eval()
        self.chat_history_ids = None

    def generate(self, text):
        new_input_ids = self.tokenizer.encode(text + self.tokenizer.eos_token, return_tensors='pt')
        bot_input_ids = torch.cat([self.chat_history_ids, new_input_ids], dim=-1) if self.chat_history_ids is not None else new_input_ids
        self.chat_history_ids = self.model.generate(bot_input_ids, max_length=1000, pad_token_id=self.tokenizer.eos_token_id, temperature=0.7, no_repeat_ngram_size=3)
        response = self.tokenizer.decode(self.chat_history_ids[:, bot_input_ids.shape[-1]:][0], skip_special_tokens=True)
        return response

使用：

chatbot = ChitChat()
while True:
    user_input = input("User: ")
    response = chatbot.generate(user_input)
    print("Bot: " + response)

请确保已经安装了 transformers 库。