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完整代码见:NLP-hands-on/天池-零基础入门NLP at main · ifwind/NLP-hands-on (github.com)
模型结构如下图所示,主要包括WordCNNEncoder、SentEncoder、SentAttention和FC模块。
最终需要做的是文档分类任务,从文档的角度出发,文档由多个句子序列组成,而句子序列由多个词组成,因此我们可以考虑从词的embedding->获取句子的embedding->再获得文档的embedding->最后根据文档的embedding对文档分类。
CNN模块常用于图像数据,Convolutional Neural Networks for Sentence Classification等论文将CNN用于文本数据,如下图所示,值得注意的是,CNN的卷积核在文本数据上,卷积核的宽度和word embedding的维度相同。
WordCNNEncoder包括三个不同卷积核大小的CNN层和相应的三个max pooling层,用于对一个句子卷积,然后max pooling得到一个句子的embedding。
SentEncoder包括多个BiLSTM层,将一篇文档中的句子序列作为输入,得到一篇文档中各个句子的embedding。
Attention中输入的一篇文档中各个句子的embedding首先经过线性变化得到key
,query
是可学习的参数矩阵,value
和key
相同,得到每个句子embedding重要性加权的一篇文档的embedding。
每个batch由多个文档组成;文档由多个句子序列组成;句子序列由多个词组成。所以输入整体模型的batch形状为:batch_size, max_doc_len, max_sent_len;
输入wordCNNEncoder的batch形状为:batch_size * max_doc_len, max_sent_len(只输入词的id);
输入SentEncoder的batch形状为:batch_size, max_doc_len,sent_rep_size;
输入Attention的batch形状为:batch_size, max_doc_len,2 * hidden_size of lstm;
输入FC的batch形状为:batch_size, 2*hidden。
根据上述流程分析,模型代码就好理解了,各个模块的模型代码如下。
WordCNNEncoder
包括两个embedding
层,分别对应batch_inputs1
,对应的embedding 层是可学习的,得到word_embed
;batch_inputs2
,读取的是外部训练好的词向量,这里用的是word2vec的词向量,是不可学习的,得到extword_embed
。将 2 个词向量相加,得到最终的词向量batch_embed
,形状是(batch_size * doc_len, sent_len, 100)
,然后添加一个维度,变为(batch_size * doc_len, 1, sent_len, 100)
,对应 Pytorch 里图像的(B, C, H, W)
。
class WordCNNEncoder(nn.Module): def __init__(self, log,vocab): super(WordCNNEncoder, self).__init__() self.log=log self.dropout = nn.Dropout(dropout) self.word_dims = 100 # 词向量的长度是 100 维 # padding_idx 表示当取第 0 个词时,向量全为 0 # 这个 Embedding 层是可学习的 self.word_embed = nn.Embedding(vocab.word_size, self.word_dims, padding_idx=0) extword_embed = vocab.load_pretrained_embs(word2vec_path,save_word2vec_embed_path) extword_size, word_dims = extword_embed.shape self.log.logger.info("Load extword embed: words %d, dims %d." % (extword_size, word_dims)) # # 这个 Embedding 层是不可学习的,通过requires_grad=False控制 self.extword_embed = nn.Embedding(extword_size, word_dims, padding_idx=0) self.extword_embed.weight.data.copy_(torch.from_numpy(extword_embed)) self.extword_embed.weight.requires_grad = False input_size = self.word_dims self.filter_sizes = [2, 3, 4] # n-gram window self.out_channel = 100 # 3 个卷积层,卷积核大小分别为 [2,100], [3,100], [4,100] self.convs = nn.ModuleList([nn.Conv2d(1, self.out_channel, (filter_size, input_size), bias=True) for filter_size in self.filter_sizes]) def forward(self, word_ids, extword_ids): # word_ids: sentence_num * sentence_len # extword_ids: sentence_num * sentence_len # batch_masks: sentence_num * sentence_len sen_num, sent_len = word_ids.shape # word_embed: sentence_num * sentence_len * 100 # 根据 index 取出词向量 word_embed = self.word_embed(word_ids) extword_embed = self.extword_embed(extword_ids) batch_embed = word_embed + extword_embed if self.training: batch_embed = self.dropout(batch_embed) # batch_embed: sentence_num x 1 x sentence_len x 100 # squeeze 是为了添加一个 channel 的维度,成为 B * C * H * W # 方便下面做 卷积 batch_embed.unsqueeze_(1) pooled_outputs = [] # 通过 3 个卷积核做 3 次卷积核池化 for i in range(len(self.filter_sizes)): # 通过池化公式计算池化后的高度: o = (i-k)/s+1 # 其中 o 表示输出的长度 # k 表示卷积核大小 # s 表示步长,这里为 1 filter_height = sent_len - self.filter_sizes[i] + 1 # conv:sentence_num * out_channel * filter_height * 1 conv = self.convs[i](batch_embed) hidden = F.relu(conv) # 定义池化层:word->sentence mp = nn.MaxPool2d((filter_height, 1)) # (filter_height, filter_width) # pooled:sentence_num * out_channel * 1 * 1 -> sen_num * out_channel # 也可以通过 squeeze 来删除无用的维度 pooled = mp(hidden).reshape(sen_num, self.out_channel) pooled_outputs.append(pooled) # 拼接 3 个池化后的向量 # reps: sen_num * (3*out_channel) reps = torch.cat(pooled_outputs, dim=1) if self.training: reps = self.dropout(reps) return reps
LSTM 的 hidden_size 为 256,由于是双向的,经过 LSTM 后的数据维度是(batch_size , doc_len, 512)
,然后和 mask 按位置相乘,把没有单词的句子的位置改为 0,最后输出的数据sent_hiddens
,维度依然是(batch_size , doc_len, 512)
。
sent_hidden_size = 256 sent_num_layers = 2 class SentEncoder(nn.Module): def __init__(self, sent_rep_size): super(SentEncoder, self).__init__() self.dropout = nn.Dropout(dropout) self.sent_lstm = nn.LSTM( input_size=sent_rep_size, # 每个句子经过 CNN(卷积+池化)后得到 300 维向量 hidden_size=sent_hidden_size,# 输出的维度 num_layers=sent_num_layers, batch_first=True, bidirectional=True ) def forward(self, sent_reps, sent_masks): # sent_reps: b * doc_len * sent_rep_size # sent_masks: b * doc_len # sent_hiddens: b * doc_len * hidden*2 # sent_hiddens: batch, seq_len, num_directions * hidden_size # containing the output features (h_t) from the last layer of the LSTM, for each t. sent_hiddens, _ = self.sent_lstm(sent_reps) # 对应相乘,用到广播,是为了只保留有句子的位置的数值 sent_hiddens = sent_hiddens * sent_masks.unsqueeze(2) if self.training: sent_hiddens = self.dropout(sent_hiddens) return sent_hiddens
query
的维度是512
,key
和query
相乘,得到outputs
并经过softmax
,维度是(batch_size , doc_len)
,表示分配到每个句子的权重。使用sent_masks
,把没有单词的句子的权重置为-1e32
,得到masked_attn_scores
。最后把masked_attn_scores
和key
相乘,得到batch_outputs
,形状是(batch_size, 512)
。
class Attention(nn.Module): def __init__(self, hidden_size): super(Attention, self).__init__() self.weight = nn.Parameter(torch.Tensor(hidden_size, hidden_size)) self.weight.data.normal_(mean=0.0, std=0.05) self.bias = nn.Parameter(torch.Tensor(hidden_size)) b = np.zeros(hidden_size, dtype=np.float32) self.bias.data.copy_(torch.from_numpy(b)) self.query = nn.Parameter(torch.Tensor(hidden_size)) self.query.data.normal_(mean=0.0, std=0.05) def forward(self, batch_hidden, batch_masks): # batch_hidden: b * doc_len * hidden_size (2 * hidden_size of lstm) # batch_masks: b x doc_len # linear # key: b * doc_len * hidden key = torch.matmul(batch_hidden, self.weight) + self.bias # compute attention # matmul 会进行广播 #outputs: b * doc_len outputs = torch.matmul(key, self.query) # 1 - batch_masks 就是取反,把没有单词的句子置为 0 # masked_fill 的作用是 在 为 1 的地方替换为 value: float(-1e32) masked_outputs = outputs.masked_fill((1 - batch_masks).bool(), float(-1e32)) #attn_scores:b * doc_len attn_scores = F.softmax(masked_outputs, dim=1) # 对于全零向量,-1e32的结果为 1/len, -inf为nan, 额外补0 masked_attn_scores = attn_scores.masked_fill((1 - batch_masks).bool(), 0.0) # sum weighted sources # masked_attn_scores.unsqueeze(1):# b * 1 * doc_len # key:b * doc_len * hidden # batch_outputs:b * hidden batch_outputs = torch.bmm(masked_attn_scores.unsqueeze(1), key).squeeze(1) return batch_outputs, attn_scores
把 WordCNNEncoder、SentEncoder、Attention、FC 全部连接起来。
class Model(nn.Module): def __init__(self,log, vocab): super(Model, self).__init__() self.log=log self.sent_rep_size = 300 # 经过 CNN 后得到的 300 维向量 self.doc_rep_size = sent_hidden_size * 2 # lstm 最后输出的向量长度 self.all_parameters = {} parameters = [] self.word_encoder = WordCNNEncoder(log,vocab) parameters.extend(list(filter(lambda p: p.requires_grad, self.word_encoder.parameters()))) self.sent_encoder = SentEncoder(self.sent_rep_size) self.sent_attention = Attention(self.doc_rep_size) parameters.extend(list(filter(lambda p: p.requires_grad, self.sent_encoder.parameters()))) parameters.extend(list(filter(lambda p: p.requires_grad, self.sent_attention.parameters()))) # doc_rep_size self.out = nn.Linear(self.doc_rep_size, vocab.label_size, bias=True) parameters.extend(list(filter(lambda p: p.requires_grad, self.out.parameters()))) if use_cuda: self.to(device) if len(parameters) > 0: self.all_parameters["basic_parameters"] = parameters self.log.logger.info('Build model with cnn word encoder, lstm sent encoder.') para_num = sum([np.prod(list(p.size())) for p in self.parameters()]) self.log.logger.info('Model param num: %.2f M.' % (para_num / 1e6)) def forward(self, batch_inputs): # batch_inputs(batch_inputs1, batch_inputs2): b * doc_len * sentence_len # batch_masks : b * doc_len * sentence_len batch_inputs1, batch_inputs2, batch_masks = batch_inputs batch_size, max_doc_len, max_sent_len = batch_inputs1.shape[0], batch_inputs1.shape[1], batch_inputs1.shape[2] # batch_inputs1: sentence_num * sentence_len batch_inputs1 = batch_inputs1.view(batch_size * max_doc_len, max_sent_len) # batch_inputs2: sentence_num * sentence_len batch_inputs2 = batch_inputs2.view(batch_size * max_doc_len, max_sent_len) # batch_masks: sentence_num * sentence_len batch_masks = batch_masks.view(batch_size * max_doc_len, max_sent_len) # sent_reps: sentence_num * sentence_rep_size # sen_num * (3*out_channel) = sen_num * 300 sent_reps = self.word_encoder(batch_inputs1, batch_inputs2) # sent_reps:b * doc_len * sent_rep_size sent_reps = sent_reps.view(batch_size, max_doc_len, self.sent_rep_size) # batch_masks:b * doc_len * max_sent_len batch_masks = batch_masks.view(batch_size, max_doc_len, max_sent_len) # sent_masks:b * doc_len any(2) 表示在 第二个维度上判断 # 表示如果如果一个句子中有词 true,那么这个句子就是 true,用于给 lstm 过滤 sent_masks = batch_masks.bool().any(2).float() # b x doc_len # sent_hiddens: b * doc_len * num_directions * hidden_size # sent_hiddens: batch, seq_len, 2 * hidden_size sent_hiddens = self.sent_encoder(sent_reps, sent_masks) # doc_reps: b * (2 * hidden_size) # atten_scores: b * doc_len doc_reps, atten_scores = self.sent_attention(sent_hiddens, sent_masks) # b * num_labels batch_outputs = self.out(doc_reps) return batch_outputs
去掉可能的标点符号,并把当前竞赛给的训练集划分为三个部分:训练集、验证集、测试集。其中,训练集用于训练,验证集用于调参,测试集用于评估线下和线上的模型效果。
这里首先用train_test_split(注意使用分层抽样)把训练集划分为训练集和测试集(9:1),然后再将训练集进一步划分为训练集和开发集(9:1).
import pandas as pd import joblib from sklearn.model_selection import train_test_split from sklearn.model_selection import StratifiedKFold def data_preprocess(): rawdata = pd.read_csv(data_file, sep='\t', encoding='UTF-8') #用正则表达式按标点替换文本 import re rawdata['words']=rawdata['text'].apply(lambda x: re.sub('3750|900|648',"",x)) del rawdata['text'] #数据划分 #如果之前已经做了就直接加载 if os.path.exists(test_index_file) and os.path.exists(train_index_file): test_index=joblib.load(test_index_file) train_index=joblib.load(train_index_file) else: rawdata.reset_index(inplace=True, drop=True) X = list(rawdata.index) y = rawdata['label'] X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.1, stratify=y) # stratify=y表示分层抽样,根据不同类别的样本占比进行抽样 test_index = {'X_test': X_test, 'y_test': y_test} joblib.dump(test_index, 'test_index.pkl') train_index = {'X_train': X_train, 'y_train': y_train} joblib.dump(train_index, 'train_index.pkl') train_x=rawdata.loc[train_index['X_train']]['words'] train_y=rawdata.loc[train_index['X_train']]['label'].values X_train, X_test, y_train, y_test = train_test_split(train_x, train_y, test_size=0.1, stratify=train_y) train_data = {'label': y_train, 'text': X_train.values} dev_data = {'label': y_test, 'text': X_test.values} #测试集 test_x=rawdata.loc[test_index['X_test']] test_y=rawdata.loc[test_index['X_test']]['label'].values test_data={'label': test_y, 'text': test_x['words'].tolist()} #预测 f = pd.read_csv(final_test_data_file, sep='\t', encoding='UTF-8') final_test_data = f['text'].apply(lambda x: re.sub('3750|900|648',"",x)) final_test_data = {'label': [0] * len(final_test_data), 'text': final_test_data.values} return train_data,dev_data,test_data,final_test_data if os.path.exists('train_data.pkl'): train_data=joblib.load('train_data.pkl') dev_data = joblib.load('dev_data.pkl') test_data = joblib.load('test_data.pkl') final_test_data = joblib.load('final_test_data.pkl') else: train_data, dev_data, test_data, final_test_data = data_preprocess() joblib.dump(train_data, 'train_data.pkl') joblib.dump(dev_data, 'dev_data.pkl') joblib.dump(test_data, 'test_data.pkl') joblib.dump(final_test_data, 'final_test_data.pkl')
根据上述模型架构的逻辑,我们需要将数据转化为所需要的batch的格式,即batch->文档->句子->词。
用get_examples和sentence_split
整理文档->句子->词;
然后用data_iter和batch_slice
将get_examples
的输出进一步整合成batch。
遍历每一篇新闻,对每篇新闻都调用sentence_split
来分割句子输入的text
表示一篇新闻,最后返回的 segments 是一个 list,其中每个元素是 tuple:(句子长度,句子本身)。
最后返回的数据是一个 list,每个元素是一个 tuple: (label, 句子数量,doc)。其中 doc 又是一个 list,每个 元素是一个 tuple: (句子长度,word_ids, extword_ids)。
# 作用是:根据一篇文章,把这篇文章分割成多个句子 # text 是一个新闻的文章 # vocab 是词典 # max_sent_len 表示每句话的长度 # max_segment 表示最多有几句话 # 最后返回的 segments 是一个list,其中每个元素是 tuple:(句子长度,句子本身) def sentence_split(text, vocab, max_sent_len=256, max_segment=16): words = text.strip().split() document_len = len(words) # 划分句子的索引,句子长度为 max_sent_len index = list(range(0, document_len, max_sent_len)) index.append(document_len) segments = [] for i in range(len(index) - 1): # 根据索引划分句子 segment = words[index[i]: index[i + 1]] assert len(segment) > 0 # 把出现太少的词替换为 UNK segment = [word if word in vocab._id2word else '<UNK>' for word in segment] # 添加 tuple:(句子长度,句子本身) segments.append([len(segment), segment]) assert len(segments) > 0 # 如果大于 max_segment 句话,则句数减少一半,返回一半的句子 if len(segments) > max_segment: segment_ = int(max_segment / 2) return segments[:segment_] + segments[-segment_:] else: # 否则返回全部句子 return segments # 最后返回的数据是一个 list,每个元素是一个 tuple: (label, 句子数量,doc) # 其中 doc 又是一个 list,每个 元素是一个 tuple: (句子长度,word_ids, extword_ids) def get_examples(data, vocab, max_sent_len=256, max_segment=8): label2id = vocab.label2id examples = [] for text, label in zip(data['text'], data['label']): # label id = label2id(label) # sents_words: 是一个list,其中每个元素是 tuple:(句子长度,句子本身) sents_words = sentence_split(text, vocab, max_sent_len, max_segment) doc = [] for sent_len, sent_words in sents_words: # 把 word 转为 id word_ids = vocab.word2id(sent_words) # 把 word 转为 ext id extword_ids = vocab.extword2id(sent_words) doc.append([sent_len, word_ids, extword_ids]) examples.append([id, len(doc), doc]) return examples
在迭代训练时,调用data_iter
函数,生成每一批的batch_data
,其中data 参数就是 get_examples() 得到的。而data_iter
函数里面会调用batch_slice
函数,把数据分割为多个 batch,组成一个 list 并返回。
# data 参数就是 get_examples() 得到的 # data是一个 list,每个元素是一个 tuple: (label, 句子数量,doc) # 其中 doc 又是一个 list,每个 元素是一个 tuple: (句子长度,word_ids, extword_ids) def data_iter(data, batch_size, shuffle=True, noise=1.0): """ randomly permute data, then sort by source length, and partition into batches ensure that the length of sentences in each batch """ batched_data = [] if shuffle: # 这里是打乱所有数据 np.random.shuffle(data) # lengths 表示的是 每篇文章的句子数量 lengths = [example[1] for example in data] noisy_lengths = [- (l + np.random.uniform(- noise, noise)) for l in lengths] sorted_indices = np.argsort(noisy_lengths).tolist() sorted_data = [data[i] for i in sorted_indices] else: sorted_data = data # 把 batch 的数据放进一个 list batched_data.extend(list(batch_slice(sorted_data, batch_size))) if shuffle: # 打乱 多个 batch np.random.shuffle(batched_data) for batch in batched_data: yield batch # build loader # data 参数就是 get_examples() 得到的 # data是一个 list,每个元素是一个 tuple: (label, 句子数量,doc) # 其中 doc 又是一个 list,每个 元素是一个 tuple: (句子长度,word_ids, extword_ids) def batch_slice(data, batch_size): batch_num = int(np.ceil(len(data) / float(batch_size))) for i in range(batch_num): # 如果 i < batch_num - 1,那么大小为 batch_size,否则就是最后一批数据 cur_batch_size = batch_size if i < batch_num - 1 else len(data) - batch_size * i docs = [data[i * batch_size + b] for b in range(cur_batch_size)] yield docs
为了将文档中的word编码为词向量的形式,需要构造词典,加载并包装Word2vec的embedding。
在字典中加入一些特殊字符,如'[PAD]', '[UNK]'
,记录需要被训练的word embedding中word对应的id和id对应的word,以及word2vec中固定embedding的extend_word对应id和id对应extend_word。
从word2vec的wv矩阵中(之前保存在txt文件中)构建embedding,为了避免每次运行都重复构建一遍,可以把生成的embedding和vocab存储起来,运行时直接加载。
# Vocab 的作用是: # 1. 创建 词 和 index 对应的字典,这里包括 2 份字典,分别是:_id2word 和 _id2extword # 其中 _id2word 是从新闻得到的, 把词频小于 5 的词替换为了 UNK。对应到模型输入的 batch_inputs1。 # _id2extword 是从 word2vec.txt 中得到的,有 5976 个词。对应到模型输入的 batch_inputs2。 # 后面会有两个 embedding 层,其中 _id2word 对应的 embedding 是可学习的,_id2extword 对应的 embedding 是从文件中加载的,是固定的 # 2.创建 label 和 index 对应的字典 class Vocab(): def __init__(self, train_data): self.min_count = 5 self.pad = 0 self.unk = 1 self._id2word = ['[PAD]', '[UNK]'] self._id2extword = ['[PAD]', '[UNK]'] self._id2label = [] self.target_names = [] self.build_vocab(train_data) reverse = lambda x: dict(zip(x, range(len(x)))) #创建词和 index 对应的字典 self._word2id = reverse(self._id2word) #创建 label 和 index 对应的字典 self._label2id = reverse(self._id2label) logging.info("Build vocab: words %d, labels %d." % (self.word_size, self.label_size)) #创建词典 def build_vocab(self, data): if os.path.exists(save_word_counter_path): self.word_counter=joblib.load(save_word_counter_path) else: self.word_counter = Counter() #计算每个词出现的次数 for text in data['text']: words = text.split() self.word_counter+=Counter(words) joblib.dump(self.word_counter,save_word_counter_path) # for word in words: # self.word_counter[word] += 1 # 去掉频次小于 min_count = 5 的词,把词存到 _id2word for word, count in self.word_counter.most_common(): if count >= self.min_count: self._id2word.append(word) label2name = {0: '科技', 1: '股票', 2: '体育', 3: '娱乐', 4: '时政', 5: '社会', 6: '教育', 7: '财经', 8: '家居', 9: '游戏', 10: '房产', 11: '时尚', 12: '彩票', 13: '星座'} self.label_counter = Counter(data['label']) for label in range(len(self.label_counter)): count = self.label_counter[label] # 取出 label 对应的次数 self._id2label.append(label) self.target_names.append(label2name[label]) # 根据label数字取出对应的名字 def load_pretrained_embs(self, embfile,save_embfile): if os.path.exists(save_embfile): embeddings= joblib.load(save_embfile) self._id2extword=embeddings['id2extword'] embeddings= embeddings['embeddings'] else: with open(embfile, encoding='utf-8') as f: lines = f.readlines() items = lines[0].split() # 第一行分别是单词数量、词向量维度 word_count, embedding_dim = int(items[0]), int(items[1]) index = len(self._id2extword) embeddings = np.zeros((word_count + index, embedding_dim)) # 下面的代码和 word2vec.txt 的结构有关 for line in lines[1:]: values = line.split() self._id2extword.append(values[0]) # 首先添加第一列的单词 vector = np.array(values[1:], dtype='float64') # 然后添加后面 100 列的词向量 embeddings[self.unk] += vector embeddings[index] = vector index += 1 # unk 的词向量是所有词的平均 embeddings[self.unk] = embeddings[self.unk] / word_count # 除以标准差干嘛? embeddings = embeddings / np.std(embeddings) joblib.dump({"embeddings":embeddings,"id2extword":self._id2extword}, save_embfile) reverse = lambda x: dict(zip(x, range(len(x)))) self._extword2id = reverse(self._id2extword) assert len(set(self._id2extword)) == len(self._id2extword) return embeddings # 根据单词得到 id def word2id(self, xs): if isinstance(xs, list): return [self._word2id.get(x, self.unk) for x in xs] return self._word2id.get(xs, self.unk) # 根据单词得到 ext id def extword2id(self, xs): if isinstance(xs, list): return [self._extword2id.get(x, self.unk) for x in xs] return self._extword2id.get(xs, self.unk) # 根据 label 得到 id def label2id(self, xs): if isinstance(xs, list): return [self._label2id.get(x, self.unk) for x in xs] return self._label2id.get(xs, self.unk) @property def word_size(self): return len(self._id2word) @property def extword_size(self): return len(self._id2extword) @property def label_size(self): return len(self._id2label)
封装各个模块的优化器操作。
class Optimizer: def __init__(self, model_parameters): self.all_params = [] self.optims = [] self.schedulers = [] for name, parameters in model_parameters.items(): if name.startswith("basic"): optim = torch.optim.Adam(parameters, lr=learning_rate) self.optims.append(optim) l = lambda step: decay ** (step // decay_step) scheduler = torch.optim.lr_scheduler.LambdaLR(optim, lr_lambda=l) self.schedulers.append(scheduler) self.all_params.extend(parameters) else: Exception("no nameed parameters.") self.num = len(self.optims) def step(self): for optim, scheduler in zip(self.optims, self.schedulers): optim.step() scheduler.step() optim.zero_grad() def zero_grad(self): for optim in self.optims: optim.zero_grad() def get_lr(self): lrs = tuple(map(lambda x: x.get_lr()[-1], self.schedulers)) lr = ' %.5f' * self.num res = lr % lrs return res
分类任务,这里选用的评价指标包括精度、召回、F1。
from sklearn.metrics import f1_score, precision_score, recall_scoredef get_score(y_ture, y_pred): y_ture = np.array(y_ture) y_pred = np.array(y_pred) f1 = f1_score(y_ture, y_pred, average='macro') * 100 p = precision_score(y_ture, y_pred, average='macro') * 100 r = recall_score(y_ture, y_pred, average='macro') * 100 return str((reformat(p, 2), reformat(r, 2), reformat(f1, 2))), reformat(f1, 2)# 保留 n 位小数点def reformat(num, n): return float(format(num, '0.' + str(n) + 'f'))
利用logging模块在控制台实时打印并及时记录运行日志。
from config import *import logging # 引入logging模块import os.pathclass Logger: def __init__(self,mode='w'): # 第一步,创建一个logger self.logger = logging.getLogger() self.logger.setLevel(logging.INFO) # Log等级总开关 # 第二步,创建一个handler,用于写入日志文件 rq = time.strftime('%Y%m%d%H%M', time.localtime(time.time())) log_path = os.getcwd() + '/Logs/' log_name = log_path + rq + '.log' logfile = log_name fh = logging.FileHandler(logfile, mode=mode) fh.setLevel(logging.DEBUG) # 输出到file的log等级的开关 # 第三步,定义handler的输出格式 formatter = logging.Formatter("%(asctime)s - %(filename)s[line:%(lineno)d] - %(levelname)s: %(message)s") fh.setFormatter(formatter) # 第四步,将logger添加到handler里面 self.logger.addHandler(fh) ch = logging.StreamHandler() ch.setLevel(logging.INFO) # 输出到console的log等级的开关 ch.setFormatter(formatter) self.logger.addHandler(ch)
batch2tensor
函数最后返回的数据是:(batch_inputs1, batch_inputs2, batch_masks), batch_labels
。形状都是(batch_size, doc_len, sent_len)
。doc_len
表示每篇新闻有几乎话,sent_len
表示每句话有多少个单词。
batch_masks
在有单词的位置,值为 1,其他地方为 0,用于后面计算 Attention,把那些没有单词的位置的 attention 改为 0。
batch_inputs1, batch_inputs2, batch_masks
,形状是(batch_size, doc_len, sent_len)
,转换为(batch_size * doc_len, sent_len)
。
# build trainerfrom tqdm import tqdmimport torchimport torch.nn as nnimport timefrom sklearn.metrics import classification_reportfrom utils import *from config import *from dataset import *class Trainer(): def __init__(self,log, model, vocab,train_data,dev_data,test_data=None,final_test_data=None): self.model = model self.report = True self.log=log # get_examples() 返回的结果是 一个 list # 每个元素是一个 tuple: (label, 句子数量,doc) # 其中 doc 又是一个 list,每个 元素是一个 tuple: (句子长度,word_ids, extword_ids) if os.path.exists('Trainer_train_data.pkl'): self.train_data = joblib.load('Trainer_train_data.pkl') self.log.logger.info('Total %d train docs.' % len(self.train_data)) self.dev_data = joblib.load('Trainer_dev_data.pkl') self.log.logger.info('Total %d dev docs.' % len(self.dev_data)) self.final_test_data = joblib.load('Trainer_final_test_data.pkl') self.log.logger.info('Total %d final test docs.' % len(self.final_test_data)) if test_data: self.test_data = joblib.load('Trainer_test_data.pkl') self.log.logger.info('Total %d test docs.' % len(self.test_data)) else: self.train_data = get_examples(train_data, vocab) self.log.logger.info('Total %d train docs.' % len(self.train_data)) self.dev_data = get_examples(dev_data, vocab) self.log.logger.info('Total %d dev docs.' % len(self.dev_data)) self.final_test_data = get_examples(final_test_data, vocab) self.log.logger.info('Total %d final test docs.' % len(self.final_test_data)) if test_data: self.test_data = get_examples(test_data, vocab) self.log.logger.info('Total %d test docs.' % len(self.test_data)) self.batch_num = int(np.ceil(len(self.train_data) / float(train_batch_size))) # criterion self.criterion = nn.CrossEntropyLoss() # label name self.target_names = vocab.target_names # optimizer self.optimizer = Optimizer(model.all_parameters) # count self.step = 0 self.early_stop = -1 self.best_train_f1, self.best_dev_f1 = 0, 0 self.last_epoch = epochs def train(self): self.log.logger.info('Start training...') pbar = tqdm(total=self.last_epoch, desc='training') for epoch in range(1, epochs + 1): train_f1 = self._train(epoch) dev_f1 = self._eval(epoch,test=1) if self.best_dev_f1 <= dev_f1: self.log.logger.info( "Exceed history dev = %.2f, current dev = %.2f" % (self.best_dev_f1, dev_f1)) torch.save(self.model.state_dict(), save_model) self.best_train_f1 = train_f1 self.best_dev_f1 = dev_f1 self.early_stop = 0 else: self.early_stop += 1 if self.early_stop == early_stops: self.log.logger.info( "Eearly stop in epoch %d, best train: %.2f, dev: %.2f" % ( epoch - early_stops, self.best_train_f1, self.best_dev_f1)) self.last_epoch = epoch break pbar.update() def test(self,flag=1): # flag = 1: dev # flag = 2: test # flag = 3: final_test self.model.load_state_dict(torch.load(save_model)) self._eval(self.last_epoch + 1, test=flag) def _train(self, epoch): self.optimizer.zero_grad() self.model.train() start_time = time.time() epoch_start_time = time.time() overall_losses = 0 losses = 0 batch_idx = 1 y_pred = [] y_true = [] pbar = tqdm(total=self.batch_num,desc='train in epoch %d'.format(epoch)) for batch_data in data_iter(self.train_data, train_batch_size, shuffle=True): torch.cuda.empty_cache() # batch_inputs: (batch_inputs1, batch_inputs2, batch_masks) # 形状都是:batch_size * doc_len * sent_len # batch_labels: batch_size batch_inputs, batch_labels = self.batch2tensor(batch_data) # batch_outputs:b * num_labels batch_outputs = self.model(batch_inputs) # criterion 是 CrossEntropyLoss,真实标签的形状是:N # 预测标签的形状是:(N,C) loss = self.criterion(batch_outputs, batch_labels) loss.backward() loss_value = loss.detach().cpu().item() losses += loss_value overall_losses += loss_value # 把预测值转换为一维,方便下面做 classification_report,计算 f1 y_pred.extend(torch.max(batch_outputs, dim=1)[1].cpu().numpy().tolist()) y_true.extend(batch_labels.cpu().numpy().tolist()) # 梯度裁剪 nn.utils.clip_grad_norm_(self.optimizer.all_params, max_norm=clip) for optimizer, scheduler in zip(self.optimizer.optims, self.optimizer.schedulers): optimizer.step() scheduler.step() self.optimizer.zero_grad() self.step += 1 if batch_idx % log_interval == 0: elapsed = time.time() - start_time lrs = self.optimizer.get_lr() self.log.logger.info( '| epoch {:3d} | step {:3d} | batch {:3d}/{:3d} | lr{} | loss {:.4f} | s/batch {:.2f}'.format( epoch, self.step, batch_idx, self.batch_num, lrs, losses / log_interval, elapsed / log_interval)) losses = 0 start_time = time.time() batch_idx += 1 pbar.update() overall_losses /= self.batch_num during_time = time.time() - epoch_start_time # reformat 保留 4 位数字 overall_losses = reformat(overall_losses, 4) score, f1 = get_score(y_true, y_pred) self.log.logger.info( '| epoch {:3d} | score {} | f1 {} | loss {:.4f} | time {:.2f}'.format(epoch, score, f1, overall_losses, during_time)) # 如果预测和真实的标签都包含相同的类别数目,才能调用 classification_report if set(y_true) == set(y_pred) and self.report: report = classification_report(y_true, y_pred, digits=4, target_names=self.target_names) self.log.logger.info('\n' + report) return f1 # 这里验证集、测试集都使用这个函数,通过 test 来区分使用哪个数据集 def _eval(self, epoch, test=1): self.model.eval() start_time = time.time() if test==1: data=self.dev_data self.log.logger.info('Start testing(dev)...') elif test==2: data = self.test_data self.log.logger.info('Start testing(test)...') elif test ==3: data = self.final_test_data self.log.logger.info('Start predicting...') y_pred = [] y_true = [] with torch.no_grad(): for batch_data in data_iter(data, test_batch_size, shuffle=False): torch.cuda.empty_cache() # batch_inputs: (batch_inputs1, batch_inputs2, batch_masks) # 形状都是:batch_size * doc_len * sent_len # batch_labels: batch_size batch_inputs, batch_labels = self.batch2tensor(batch_data) # batch_outputs:b * num_labels batch_outputs = self.model(batch_inputs) # 把预测值转换为一维,方便下面做 classification_report,计算 f1 y_pred.extend(torch.max(batch_outputs, dim=1)[1].cpu().numpy().tolist()) y_true.extend(batch_labels.cpu().numpy().tolist()) score, f1 = get_score(y_true, y_pred) during_time = time.time() - start_time if test==3: df = pd.DataFrame({'label': y_pred}) df.to_csv(save_test, index=False, sep=',') else: self.log.logger.info( '| epoch {:3d} | dev | score {} | f1 {} | time {:.2f}'.format(epoch, score, f1, during_time)) if set(y_true) == set(y_pred) and self.report: report = classification_report(y_true, y_pred, digits=4, target_names=self.target_names) self.log.logger.info('\n' + report) return f1 # data 参数就是 get_examples() 得到的,经过了分 batch # batch_data是一个 list,每个元素是一个 tuple: (label, 句子数量,doc) # 其中 doc 又是一个 list,每个 元素是一个 tuple: (句子长度,word_ids, extword_ids) def batch2tensor(self, batch_data): ''' [[label, doc_len, [[sent_len, [sent_id0, ...], [sent_id1, ...]], ...]] ''' batch_size = len(batch_data) doc_labels = [] doc_lens = [] doc_max_sent_len = [] for doc_data in batch_data: # doc_data 代表一篇新闻,是一个 tuple: (label, 句子数量,doc) # doc_data[0] 是 label doc_labels.append(doc_data[0]) # doc_data[1] 是 这篇文章的句子数量 doc_lens.append(doc_data[1]) # doc_data[2] 是一个 list,每个 元素是一个 tuple: (句子长度,word_ids, extword_ids) # 所以 sent_data[0] 表示每个句子的长度(单词个数) sent_lens = [sent_data[0] for sent_data in doc_data[2]] # 取出这篇新闻中最长的句子长度(单词个数) max_sent_len = max(sent_lens) doc_max_sent_len.append(max_sent_len) # 取出最长的句子数量 max_doc_len = max(doc_lens) # 取出这批 batch 数据中最长的句子长度(单词个数) max_sent_len = max(doc_max_sent_len) # 创建 数据 batch_inputs1 = torch.zeros((batch_size, max_doc_len, max_sent_len), dtype=torch.int64) batch_inputs2 = torch.zeros((batch_size, max_doc_len, max_sent_len), dtype=torch.int64) batch_masks = torch.zeros((batch_size, max_doc_len, max_sent_len), dtype=torch.float32) batch_labels = torch.LongTensor(doc_labels) for b in range(batch_size): for sent_idx in range(doc_lens[b]): # batch_data[b][2] 表示一个 list,是一篇文章中的句子 sent_data = batch_data[b][2][sent_idx] #sent_data 表示一个句子 for word_idx in range(sent_data[0]): # sent_data[0] 是句子长度(单词数量) # sent_data[1] 表示 word_ids batch_inputs1[b, sent_idx, word_idx] = sent_data[1][word_idx] # # sent_data[2] 表示 extword_ids batch_inputs2[b, sent_idx, word_idx] = sent_data[2][word_idx] # mask 表示 哪个位置是有词,后面计算 attention 时,没有词的地方会被置为 0 batch_masks[b, sent_idx, word_idx] = 1 if use_cuda: batch_inputs1 = batch_inputs1.to(device) batch_inputs2 = batch_inputs2.to(device) batch_masks = batch_masks.to(device) batch_labels = batch_labels.to(device) return (batch_inputs1, batch_inputs2, batch_masks), batch_labels
log=Logger(mode='w')log.logger.info("Dataset has built.")#构建词典vocab=Vocab(train_data)log.logger.info("Vocab has built.")log.logger.info("Creating Model.")#创建模型model=Model(log,vocab)log.logger.info("Use cuda: %s, gpu id: %d.", use_cuda, gpu)# traintrainer = Trainer(log,model, vocab,train_data,dev_data,test_data,final_test_data)trainer.train()# testtrainer.test(flag=2)trainer.test(flag=3)
2021-10-16 00:13:20,628 - train.py[line:136] - INFO: | epoch 10 | step 5747 | batch 50/633 | lr 0.00005 | loss 0.2194 | s/batch 5.052021-10-16 00:17:49,770 - train.py[line:136] - INFO: | epoch 10 | step 5797 | batch 100/633 | lr 0.00005 | loss 0.2107 | s/batch 5.382021-10-16 00:22:03,411 - train.py[line:136] - INFO: | epoch 10 | step 5847 | batch 150/633 | lr 0.00005 | loss 0.2299 | s/batch 5.072021-10-16 00:26:03,440 - train.py[line:136] - INFO: | epoch 10 | step 5897 | batch 200/633 | lr 0.00005 | loss 0.2170 | s/batch 4.802021-10-16 00:30:41,771 - train.py[line:136] - INFO: | epoch 10 | step 5947 | batch 250/633 | lr 0.00005 | loss 0.2178 | s/batch 5.572021-10-16 00:35:08,509 - train.py[line:136] - INFO: | epoch 10 | step 5997 | batch 300/633 | lr 0.00005 | loss 0.2189 | s/batch 5.332021-10-16 00:39:21,883 - train.py[line:136] - INFO: | epoch 10 | step 6047 | batch 350/633 | lr 0.00004 | loss 0.2196 | s/batch 5.072021-10-16 00:43:11,833 - train.py[line:136] - INFO: | epoch 10 | step 6097 | batch 400/633 | lr 0.00004 | loss 0.2100 | s/batch 4.602021-10-16 00:47:09,737 - train.py[line:136] - INFO: | epoch 10 | step 6147 | batch 450/633 | lr 0.00004 | loss 0.1975 | s/batch 4.762021-10-16 00:51:06,759 - train.py[line:136] - INFO: | epoch 10 | step 6197 | batch 500/633 | lr 0.00004 | loss 0.2076 | s/batch 4.742021-10-16 00:55:23,886 - train.py[line:136] - INFO: | epoch 10 | step 6247 | batch 550/633 | lr 0.00004 | loss 0.2091 | s/batch 5.142021-10-16 00:59:17,891 - train.py[line:136] - INFO: | epoch 10 | step 6297 | batch 600/633 | lr 0.00004 | loss 0.1987 | s/batch 4.682021-10-16 01:01:58,372 - train.py[line:155] - INFO: | epoch 10 | score (92.32, 91.34, 91.82) | f1 91.82 | loss 0.2124 | time 3169.872021-10-16 01:01:58,631 - train.py[line:161] - INFO: precision recall f1-score support 科技 0.9311 0.9330 0.9320 31524 股票 0.9390 0.9467 0.9428 29926 体育 0.9843 0.9846 0.9844 25454 娱乐 0.9420 0.9530 0.9475 17928 时政 0.8763 0.8996 0.8878 12163 社会 0.8704 0.8652 0.8678 9908 教育 0.9354 0.9263 0.9309 8088 财经 0.8753 0.8295 0.8518 7161 家居 0.9078 0.9045 0.9061 6356 游戏 0.9183 0.8899 0.9039 4761 房产 0.9827 0.9716 0.9772 3985 时尚 0.8955 0.8782 0.8867 2536 彩票 0.9395 0.9051 0.9220 1475 星座 0.9272 0.9007 0.9137 735 accuracy 0.9316 162000 macro avg 0.9232 0.9134 0.9182 162000weighted avg 0.9315 0.9316 0.9315 1620002021-10-16 01:01:58,634 - train.py[line:171] - INFO: Start testing(dev)...2021-10-16 01:07:47,322 - train.py[line:201] - INFO: | epoch 10 | dev | score (93.68, 93.08, 93.36) | f1 93.36 | time 348.692021-10-16 01:07:47,352 - train.py[line:206] - INFO: precision recall f1-score support 科技 0.9312 0.9546 0.9428 3502 股票 0.9618 0.9456 0.9536 3325 体育 0.9838 0.9866 0.9852 2828 娱乐 0.9540 0.9583 0.9562 1992 时政 0.8670 0.9267 0.8959 1351 社会 0.8862 0.8556 0.8706 1101 教育 0.9421 0.9232 0.9326 899 财经 0.9133 0.8869 0.8999 796 家居 0.9508 0.9037 0.9267 706 游戏 0.9576 0.8960 0.9258 529 房产 0.9932 0.9910 0.9921 443 时尚 0.9204 0.9433 0.9317 282 彩票 0.9387 0.9329 0.9358 164 星座 0.9157 0.9268 0.9212 82 accuracy 0.9423 18000 macro avg 0.9368 0.9308 0.9336 18000weighted avg 0.9427 0.9423 0.9423 180002021-10-16 01:07:47,353 - train.py[line:65] - INFO: Exceed history dev = 93.22, current dev = 93.362021-10-16 16:05:00,917 - train.py[line:180] - INFO: Start testing(test)...2021-10-16 16:11:41,817 INFO: | epoch 11 | dev | score (93.68, 93.29, 93.45) | f1 93.45 | time 400.902021-10-16 16:11:41,817 - train.py[line:207] - INFO: | epoch 11 | dev | score (93.68, 93.29, 93.45) | f1 93.45 | time 400.902021-10-16 16:11:41,849 INFO: precision recall f1-score support 科技 0.9325 0.9514 0.9419 3892 股票 0.9541 0.9461 0.9501 3694 体育 0.9879 0.9876 0.9877 3143 娱乐 0.9554 0.9575 0.9564 2213 时政 0.8804 0.9361 0.9074 1502 社会 0.8826 0.8733 0.8779 1223 教育 0.9470 0.9309 0.9389 998 财经 0.9056 0.8360 0.8694 884 家居 0.9501 0.9223 0.9360 785 游戏 0.9711 0.9133 0.9413 588 房产 0.9899 0.9959 0.9929 492 时尚 0.9214 0.9361 0.9287 313 彩票 0.9602 0.9286 0.9441 182 星座 0.8776 0.9451 0.9101 91 accuracy 0.9431 20000 macro avg 0.9368 0.9329 0.9345 20000weighted avg 0.9434 0.9431 0.9430 20000
最终在线上的成绩为:0.9324。
自然语言中的CNN–TextCNN(基础篇) - 知乎 (zhihu.com)
ALBERT — transformers 4.11.3 documentation (huggingface.co)
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BERT实战——(1)文本分类 | 冬于的博客 (ifwind.github.io)
阅读源码-理解pytorch_pretrained_bert中BertTokenizer工作方式_枪枪枪的博客-CSDN博客
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NLP学习1 - 使用Huggingface Transformers框架从头训练语言模型 - 简书 (jianshu.com)
零基础入门NLP-阿里云tianchi新闻文本分类大赛rank4分享-代码+经验/Huggingface Bert tutorial - 知乎 (zhihu.com)
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