|
| 1 | +import torch |
| 2 | +import torch.nn.functional as F |
| 3 | +import os |
| 4 | +import argparse |
| 5 | +from tqdm import trange |
| 6 | +from transformers import GPT2LMHeadModel, GPT2Config, CpmTokenizer |
| 7 | +from utils import top_k_top_p_filtering, set_logger |
| 8 | +from os.path import join, exists |
| 9 | + |
| 10 | + |
| 11 | +def generate_next_token(input_ids): |
| 12 | + """ |
| 13 | + 对于给定的上文,生成下一个单词 |
| 14 | + """ |
| 15 | + outputs = model(input_ids=input_ids) |
| 16 | + logits = outputs.logits |
| 17 | + # next_token_logits表示最后一个token的hidden_state对应的prediction_scores,也就是模型要预测的下一个token的概率 |
| 18 | + next_token_logits = logits[0, -1, :] |
| 19 | + next_token_logits = next_token_logits / args.temperature |
| 20 | + # 对于<unk>的概率设为无穷小,也就是说模型的预测结果不可能是[UNK]这个token |
| 21 | + next_token_logits[unk_id] = -float('Inf') |
| 22 | + filtered_logits = top_k_top_p_filtering(next_token_logits, top_k=args.topk, top_p=args.topp) |
| 23 | + # torch.multinomial表示从候选集合中选出无放回地进行抽取num_samples个元素,权重越高,抽到的几率越高,返回元素的下标 |
| 24 | + next_token_id = torch.multinomial(F.softmax(filtered_logits, dim=-1), num_samples=1) |
| 25 | + return next_token_id |
| 26 | + |
| 27 | + |
| 28 | +def generate(max_len): |
| 29 | + # 对title与context进行tokenize |
| 30 | + title_ids = tokenizer.encode(title, add_special_tokens=False) |
| 31 | + context_ids = tokenizer.encode(context, add_special_tokens=False) |
| 32 | + input_ids = title_ids + [sep_id] + context_ids |
| 33 | + cur_len = len(input_ids) |
| 34 | + last_token_id = input_ids[-1] # 已生成的内容的最后一个token |
| 35 | + input_ids = torch.tensor([input_ids], dtype=torch.long, device=device) |
| 36 | + |
| 37 | + while True: |
| 38 | + next_token_id = generate_next_token(input_ids) |
| 39 | + input_ids = torch.cat((input_ids, next_token_id.unsqueeze(0)), dim=1) |
| 40 | + cur_len += 1 |
| 41 | + word = tokenizer.convert_ids_to_tokens(next_token_id.item()) |
| 42 | + # if cur_len >= max_len: |
| 43 | + # break |
| 44 | + # 超过最大长度,并且换行 |
| 45 | + if cur_len >= max_len and last_token_id == 8 and next_token_id == 3: |
| 46 | + break |
| 47 | + # 超过最大长度,并且生成标点符号 |
| 48 | + if cur_len >= max_len and word in [".", "。", "!", "!", "?", "?", ",", ","]: |
| 49 | + break |
| 50 | + # 生成结束符 |
| 51 | + if next_token_id == eod_id: |
| 52 | + break |
| 53 | + result = tokenizer.decode(input_ids.squeeze(0)) |
| 54 | + return result |
| 55 | + |
| 56 | + |
| 57 | +if __name__ == '__main__': |
| 58 | + # 参数设置 |
| 59 | + parser = argparse.ArgumentParser() |
| 60 | + parser.add_argument('--device', default='0', type=str, required=False, help='生成设备') |
| 61 | + parser.add_argument('--temperature', default=1, type=float, required=False, help='生成温度') |
| 62 | + parser.add_argument('--topk', default=0, type=int, required=False, help='最高几选一') |
| 63 | + parser.add_argument('--topp', default=0.85, type=float, required=False, help='最高积累概率') |
| 64 | + parser.add_argument('--repetition_penalty', default=1.0, type=float, required=False, help='重复惩罚参数') |
| 65 | + parser.add_argument('--max_len', default=200, type=int, required=False, help='生成的最长长度') |
| 66 | + parser.add_argument('--log_path', default='log/generate.log', type=str, required=False, help='日志存放位置') |
| 67 | + parser.add_argument('--no_cuda', action='store_true', help='不使用GPU进行预测') |
| 68 | + parser.add_argument('--model_path', type=str, default='model/zuowen_epoch40', help='模型存放位置') |
| 69 | + # parser.add_argument('--title', type=str, default='徜徉在书籍的阳光世界', help='作文标题') |
| 70 | + # parser.add_argument('--context', type=str, default='一本书是一个人的眼睛,它可以让你看到另一个世界的奇妙', help='作文上文') |
| 71 | + parser.add_argument('--title', type=str, default='家乡的四季', help='作文标题') |
| 72 | + parser.add_argument('--context', type=str, default='家乡的四季,最美不过了', help='作文上文') |
| 73 | + args = parser.parse_args() |
| 74 | + |
| 75 | + os.environ["CUDA_VISIBLE_DEVICES"] = args.device # 此处设置程序使用哪些显卡 |
| 76 | + args.cuda = torch.cuda.is_available() and not args.no_cuda # 当用户使用GPU,并且GPU可用时 |
| 77 | + device = 'cuda:0' if args.cuda else 'cpu' |
| 78 | + # device = 'cpu' |
| 79 | + |
| 80 | + # 创建日志对象 |
| 81 | + logger = set_logger(args.log_path) |
| 82 | + |
| 83 | + # 初始化tokenizer |
| 84 | + tokenizer = CpmTokenizer(vocab_file="vocab/chinese_vocab.model") |
| 85 | + eod_id = tokenizer.convert_tokens_to_ids("<eod>") # 文档结束符 |
| 86 | + sep_id = tokenizer.sep_token_id |
| 87 | + unk_id = tokenizer.unk_token_id |
| 88 | + |
| 89 | + # 加载模型 |
| 90 | + model = GPT2LMHeadModel.from_pretrained(args.model_path) |
| 91 | + model.eval() |
| 92 | + model = model.to(device) |
| 93 | + |
| 94 | + title = args.title |
| 95 | + context = args.context |
| 96 | + logger.info("title:{}".format(title)) |
| 97 | + logger.info("context:{}".format(context)) |
| 98 | + |
| 99 | + # 开始生成 |
| 100 | + result = generate(args.max_len) |
| 101 | + result = result.split("<sep>")[1] |
| 102 | + logger.info("result:{}\n".format(result)) |
| 103 | + |
| 104 | + # 通过控制台循环生成 |
| 105 | + # print('开始生成,输入CTRL + Z以退出') |
| 106 | + # while True: |
| 107 | + # try: |
| 108 | + # # 用户输入title与context |
| 109 | + # title = input("请输入作文标题:") |
| 110 | + # context = input("请输入作文起始句子:") |
| 111 | + # |
| 112 | + # logger.info("title:{}".format(title)) |
| 113 | + # logger.info("context:{}".format(context)) |
| 114 | + # |
| 115 | + # # 开始生成 |
| 116 | + # result = generate(args.max_len) |
| 117 | + # result = result.split("<sep>")[1] |
| 118 | + # logger.info("result:{}\n".format(result)) |
| 119 | + # break |
| 120 | + # |
| 121 | + # except KeyboardInterrupt: |
| 122 | + # break |
| 123 | + |
| 124 | + |
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