拥有多种人格的对话代理系统（PersonaGPT）

PersonaGPT是一个针对开放领域的对话代理系统，旨在完成两项任务：

它基于 GPT-2 结构的 DialoGPT-medium 预训练模型进行构建。该模型在 Persona-Chat 数据集上进行训练，并添加了特殊标记以更好地区分对话历史和人格特征。此外，还使用了一些主动学习方法，以训练模型通过转换级别目标进行受控解码。

完整存储库

有关预处理、训练和实现细节，请参阅 personaGPT repo 。

如何使用

from transformers import GPT2Tokenizer, GPT2LMHeadModel
import torch
tokenizer = AutoTokenizer.from_pretrained("af1tang/personaGPT")
model = AutoModelForCausalLM.from_pretrained("af1tang/personaGPT")
if torch.cuda.is_available():
    model = model.cuda()
## utility functions ##
flatten = lambda l: [item for sublist in l for item in sublist]

def to_data(x):
    if torch.cuda.is_available():
        x = x.cpu()
    return x.data.numpy()

def to_var(x):
    if not torch.is_tensor(x):
        x = torch.Tensor(x)
    if torch.cuda.is_available():
        x = x.cuda()
    return x

def display_dialog_history(dialog_hx):
    for j, line in enumerate(dialog_hx):
        msg = tokenizer.decode(line)
        if j %2 == 0:
            print(">> User: "+ msg)
        else:
            print("Bot: "+msg)
            print()

def generate_next(bot_input_ids, do_sample=True, top_k=10, top_p=.92,
                  max_length=1000, pad_token=tokenizer.eos_token_id):
    full_msg = model.generate(bot_input_ids, do_sample=True,
                                              top_k=top_k, top_p=top_p, 
                                              max_length=max_length, pad_token_id=tokenizer.eos_token_id)
    msg = to_data(full_msg.detach()[0])[bot_input_ids.shape[-1]:]
    return msg

# get personality facts for conversation
personas = []
for i in range(3):
    response = input(">> Fact %d: "%(i+1))+ tokenizer.eos_token
    personas.append(response)
personas = tokenizer.encode(''.join(['<|p2|>'] + personas + ['<|sep|>'] + ['<|start|>']))

# converse for 8 turns
dialog_hx = []
for step in range(8):
    # encode the user input
    user_inp = tokenizer.encode(input(">> User: ") + tokenizer.eos_token)
    # append to the chat history
    dialog_hx.append(user_inp)
        
    # generated a response while limiting the total chat history to 1000 tokens, 
    bot_input_ids = to_var([personas + flatten(dialog_hx)]).long()
    msg = generate_next(bot_input_ids)
    dialog_hx.append(msg)
    print("Bot: {}".format(tokenizer.decode(msg, skip_special_tokens=True)))

个性化解码示例：

## available actions ##
action_space = [ 'ask about kids.', "ask about pets.", 'talk about work.', 
               'ask about marital status.', 'talk about travel.', 'ask about age and gender.',
        'ask about hobbies.', 'ask about favorite food.', 'talk about movies.', 
        'talk about music.', 'talk about politics.']
# converse for 8 turns
dialog_hx = []
for step in range(8):
    # choose an action
    act = None
    while act not in action_space:
        display_dialog_history(dialog_hx)
        print()
        print(" actions: ")
        for k,v in enumerate(action_space): print(k,v)
        try:
            act = action_space[int(input(" input [0-10]: " ))]
        except:
            act = None
    print()
    # format into prefix code
    action_prefix = tokenizer.encode(''.join(['<|act|> '] + [act] + ['<|p1|>'] + [] + ['<|sep|>'] + ['<|start|>']))
    bot_input_ids = to_var([action_prefix + flatten(dialog_hx)]).long()
    
    # generate query conditioned on action
    msg = generate_next(bot_input_ids, top_k=top_k, top_p=top_p, max_length=max_length)
    dialog_hx.append(msg)
    
    # generate bot response
    bot_input_ids = to_var([personas+ flatten(dialog_hx)]).long()
    msg = generate_next(bot_input_ids, top_k=top_k, top_p=top_p, max_length=max_length)
    dialog_hx.append(msg)
display_dialog_history(dialog_hx)

受控响应生成示例：