【关于 Bert 源码解析V 之 文本相似度 篇 】 那些的你不知道的事
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·
2021-02-11 06:01
作者：杨夕
论文链接：https://arxiv.org/pdf/1810.04805.pdf
本文链接：https://github.com/km1994/nlp_paper_study
个人介绍：大佬们好，我叫杨夕，该项目主要是本人在研读顶会论文和复现经典论文过程中，所见、所思、所想、所闻，可能存在一些理解错误，希望大佬们多多指正。
【注：手机阅读可能图片打不开！！！】
目录
一、动机
之前给 小伙伴们 写过 一篇 【【关于Bert】 那些的你不知道的事】后，有一些小伙伴联系我，说对 【Bert】 里面的很多细节性问题都没看懂，不清楚他怎么实现的。针对该问题，小菜鸡的我 也 意识到自己的不足，所以就 想 研读一下 【Bert】 的 源码，并针对 之前小伙伴 的一些 问题 进行 回答和解释，能力有限，希望对大家有帮助。
二、本文框架
本文 将 【Bert】 的 源码分成以下模块：
【关于 Bert 源码解析 之 主体篇 】 那些的你不知道的事
【关于 Bert 源码解析 之 预训练篇 】 那些的你不知道的事
【关于 Bert 源码解析 之 微调篇 】 那些的你不知道的事
【关于 Bert 源码解析IV 之 句向量生成篇 】 那些的你不知道的事
【关于 Bert 源码解析V 之 文本相似度篇 】 那些的你不知道的事【本章】
分模块 进行解读。
三、前言
本文 主要 解读 Bert 模型的 微调 模块代码：
similarity.py：主要用于 计算文本相似度
四、配置类 （Config）
该类主要包含 一些 Bert 模型地址，和一些采用配置信息
import os
import tensorflow as tf
class Config():
def __init__(self):
tf.logging.set_verbosity(tf.logging.INFO)
self.file_path = os.path.dirname(__file__)
# Bert 模型 的 路径
self.model_dir = os.path.join(self.file_path, 'F:/document/datasets/nlpData/bert/chinese_L-12_H-768_A-12/')
# Bert 模型 配置
self.config_name = os.path.join(self.model_dir, 'bert_config.json')
# Bert 模型 文件
self.ckpt_name = os.path.join(self.model_dir, 'bert_model.ckpt')
# Bert 输出
self.output_dir = os.path.join("", 'output/')
# Bert 词库
self.vocab_file = os.path.join(self.model_dir, 'vocab.txt')
# 训练数据地址
self.data_dir = os.path.join("", 'data/')
# 训练 epochs
self.num_train_epochs = 10
# 训练 batch_size
self.batch_size = 128
self.learning_rate = 0.00005
# gpu使用率
self.gpu_memory_fraction = 0.8
# 默认取倒数第二层的输出值作为句向量
self.layer_indexes = [-2]
# 序列的最大程度，单文本建议把该值调小
self.max_seq_len = 32
五、特征实例类 （InputExample）
这部分 代码在 【关于 Bert 源码解析 之 微调篇 】 那些的你不知道的事 有做过详细介绍，此处不展开重新介绍
class InputExample(object):
def __init__(self, unique_id, text_a, text_b):
self.unique_id = unique_id
self.text_a = text_a
self.text_b = text_b
class InputFeatures(object):
"""A single set of features of data."""
def __init__(self, unique_id, tokens, input_ids, input_mask, input_type_ids):
self.unique_id = unique_id
self.tokens = tokens
self.input_ids = input_ids
self.input_mask = input_mask
self.input_type_ids = input_type_ids
六、数据预处理类
6.1 DataProcessor
class DataProcessor(object):
"""Base class for data converters for sequence classification data sets."""
def get_train_examples(self, data_dir):
"""Gets a collection of `InputExample`s for the train set."""
raise NotImplementedError()
def get_dev_examples(self, data_dir):
"""Gets a collection of `InputExample`s for the dev set."""
raise NotImplementedError()
def get_test_examples(self, data_dir):
"""Gets a collection of `InputExample`s for prediction."""
raise NotImplementedError()
def get_labels(self):
"""Gets the list of labels for this data set."""
raise NotImplementedError()
6.3 文本相似度任务 文本预处理 （SimProcessor）
6.3.1 数据格式
query,reply,label
可以组合贷吗？,可以的,1
...
从上面实例中可以看出，每一行有query,reply,label组成，该任务主要是 判别 query 与 reply 是否存在关系，当 label 为 1 时，表示存在关系，为 0 时，表示无关系；
6.3.2 数据预处理类
class SimProcessor(DataProcessor):
# 加载 训练数据
def get_train_examples(self, data_dir):
file_path = os.path.join(data_dir, 'train.csv')
train_df = pd.read_csv(file_path, encoding='utf-8')
train_data = []
for index, train in enumerate(train_df.values):
guid = 'train-%d' % index
text_a = tokenization.convert_to_unicode(str(train[0]))
text_b = tokenization.convert_to_unicode(str(train[1]))
label = str(train[2])
train_data.append(InputExample(guid=guid, text_a=text_a, text_b=text_b, label=label))
random.shuffle(train_data)
return train_data
# 加载 验证数据
def get_dev_examples(self, data_dir):
file_path = os.path.join(data_dir, 'dev.csv')
dev_df = pd.read_csv(file_path, encoding='utf-8')
dev_data = []
for index, dev in enumerate(dev_df.values):
guid = 'test-%d' % index
text_a = tokenization.convert_to_unicode(str(dev[0]))
text_b = tokenization.convert_to_unicode(str(dev[1]))
label = str(dev[2])
dev_data.append(InputExample(guid=guid, text_a=text_a, text_b=text_b, label=label))
random.shuffle(dev_data)
return dev_data
def get_test_examples(self, data_dir):
file_path = os.path.join(data_dir, 'test.csv')
test_df = pd.read_csv(file_path, encoding='utf-8')
test_data = []
for index, test in enumerate(test_df.values):
test_data.append([str(test[0]),str(test[1])])
return test_data
def get_sentence_examples(self, questions):
for index, data in enumerate(questions):
guid = 'test-%d' % index
text_a = tokenization.convert_to_unicode(str(data[0]))
text_b = tokenization.convert_to_unicode(str(data[1]))
label = str(0)
yield InputExample(guid=guid, text_a=text_a, text_b=text_b, label=label)
# 获取标签
def get_labels(self):
return ['0', '1']
七、基于 Bert 的 文本相似度 模型
这部分代码，很多方法都未作修改， 与 【关于 Bert 源码解析 之 微调篇 】 那些的你不知道的事 一样，
class BertSim:
def __init__(self, batch_size=args.batch_size):
self.mode = None
self.max_seq_length = args.max_seq_len
self.tokenizer = tokenization.FullTokenizer(vocab_file=args.vocab_file, do_lower_case=True)
self.batch_size = batch_size
self.estimator = None
self.processor = SimProcessor()
tf.logging.set_verbosity(tf.logging.INFO)
# 选择模式
def set_mode(self, mode):
self.mode = mode
self.estimator = self.get_estimator()
if mode == tf.estimator.ModeKeys.PREDICT:
self.input_queue = Queue(maxsize=1)
self.output_queue = Queue(maxsize=1)
self.predict_thread = Thread(target=self.predict_from_queue, daemon=True)
self.predict_thread.start()
if mode == "test":
self.input_queue = Queue(maxsize=1)
self.output_queue = Queue(maxsize=1)
self.predict_thread = Thread(target=self.predict_from_queue, daemon=True)
self.predict_thread.start()
# 构建模型
@staticmethod
def create_model(bert_config, is_training, input_ids, input_mask, segment_ids,
labels, num_labels, use_one_hot_embeddings):
"""Creates a classification model."""
model = modeling.BertModel(
config=bert_config,
is_training=is_training,
input_ids=input_ids,
input_mask=input_mask,
token_type_ids=segment_ids,
use_one_hot_embeddings=use_one_hot_embeddings)
# In the demo, we are doing a simple classification task on the entire
# segment.
#
# If you want to use the token-level output, use model.get_sequence_output()
# instead.
output_layer = model.get_pooled_output()
hidden_size = output_layer.shape[-1].value
output_weights = tf.get_variable(
"output_weights", [num_labels, hidden_size],
initializer=tf.truncated_normal_initializer(stddev=0.02))
output_bias = tf.get_variable(
"output_bias", [num_labels], initializer=tf.zeros_initializer())
with tf.variable_scope("loss"):
if is_training:
# I.e., 0.1 dropout
output_layer = tf.nn.dropout(output_layer, keep_prob=0.9)
logits = tf.matmul(output_layer, output_weights, transpose_b=True)
logits = tf.nn.bias_add(logits, output_bias)
probabilities = tf.nn.softmax(logits, axis=-1)
log_probs = tf.nn.log_softmax(logits, axis=-1)
one_hot_labels = tf.one_hot(labels, depth=num_labels, dtype=tf.float32)
per_example_loss = -tf.reduce_sum(one_hot_labels * log_probs, axis=-1)
loss = tf.reduce_mean(per_example_loss)
return (loss, per_example_loss, logits, probabilities)
def model_fn_builder(self, bert_config, num_labels, init_checkpoint, learning_rate,
num_train_steps, num_warmup_steps,
use_one_hot_embeddings):
"""Returns `model_fn` closurimport_tfe for TPUEstimator."""
def model_fn(features, labels, mode, params): # pylint: disable=unused-argument
from tensorflow.python.estimator.model_fn import EstimatorSpec
tf.logging.info("*** Features ***")
for name in sorted(features.keys()):
tf.logging.info(" name = %s, shape = %s" % (name, features[name].shape))
input_ids = features["input_ids"]
input_mask = features["input_mask"]
segment_ids = features["segment_ids"]
label_ids = features["label_ids"]
is_training = (mode == tf.estimator.ModeKeys.TRAIN)
(total_loss, per_example_loss, logits, probabilities) = BertSim.create_model(
bert_config, is_training, input_ids, input_mask, segment_ids, label_ids,
num_labels, use_one_hot_embeddings)
tvars = tf.trainable_variables()
initialized_variable_names = {}
if init_checkpoint:
(assignment_map, initialized_variable_names) \
= modeling.get_assignment_map_from_checkpoint(tvars, init_checkpoint)
tf.train.init_from_checkpoint(init_checkpoint, assignment_map)
tf.logging.info("**** Trainable Variables ****")
for var in tvars:
init_string = ""
if var.name in initialized_variable_names:
init_string = ", *INIT_FROM_CKPT*"
tf.logging.info(" name = %s, shape = %s%s", var.name, var.shape,
init_string)
if mode == tf.estimator.ModeKeys.TRAIN:
train_op = optimization.create_optimizer(
total_loss, learning_rate, num_train_steps, num_warmup_steps, False)
output_spec = EstimatorSpec(
mode=mode,
loss=total_loss,
train_op=train_op)
elif mode == tf.estimator.ModeKeys.EVAL:
def metric_fn(per_example_loss, label_ids, logits):
predictions = tf.argmax(logits, axis=-1, output_type=tf.int32)
accuracy = tf.metrics.accuracy(label_ids, predictions)
auc = tf.metrics.auc(label_ids, predictions)
loss = tf.metrics.mean(per_example_loss)
return {
"eval_accuracy": accuracy,
"eval_auc": auc,
"eval_loss": loss,
}
eval_metrics = metric_fn(per_example_loss, label_ids, logits)
output_spec = EstimatorSpec(
mode=mode,
loss=total_loss,
eval_metric_ops=eval_metrics)
else:
output_spec = EstimatorSpec(mode=mode, predictions=probabilities)
return output_spec
return model_fn
def get_estimator(self):
from tensorflow.python.estimator.estimator import Estimator
from tensorflow.python.estimator.run_config import RunConfig
bert_config = modeling.BertConfig.from_json_file(args.config_name)
label_list = self.processor.get_labels()
train_examples = self.processor.get_train_examples(args.data_dir)
num_train_steps = int(
len(train_examples) / self.batch_size * args.num_train_epochs)
num_warmup_steps = int(num_train_steps * 0.1)
if self.mode == tf.estimator.ModeKeys.TRAIN:
init_checkpoint = args.ckpt_name
else:
init_checkpoint = args.output_dir
model_fn = self.model_fn_builder(
bert_config=bert_config,
num_labels=len(label_list),
init_checkpoint=init_checkpoint,
learning_rate=args.learning_rate,
num_train_steps=num_train_steps,
num_warmup_steps=num_warmup_steps,
use_one_hot_embeddings=False)
config = tf.ConfigProto()
config.gpu_options.allow_growth = True
config.gpu_options.per_process_gpu_memory_fraction = args.gpu_memory_fraction
config.log_device_placement = False
return Estimator(model_fn=model_fn, config=RunConfig(session_config=config), model_dir=args.output_dir,
params={'batch_size': self.batch_size})
def predict_from_queue(self):
for i in self.estimator.predict(input_fn=self.queue_predict_input_fn, yield_single_examples=False):
self.output_queue.put(i)
def queue_predict_input_fn(self):
return (tf.data.Dataset.from_generator(
self.generate_from_queue,
output_types={
'input_ids': tf.int32,
'input_mask': tf.int32,
'segment_ids': tf.int32,
'label_ids': tf.int32},
output_shapes={
'input_ids': (None, self.max_seq_length),
'input_mask': (None, self.max_seq_length),
'segment_ids': (None, self.max_seq_length),
'label_ids': (1,)}).prefetch(10))
def convert_examples_to_features(self, examples, label_list, max_seq_length, tokenizer):
"""Convert a set of `InputExample`s to a list of `InputFeatures`."""
for (ex_index, example) in enumerate(examples):
label_map = {}
for (i, label) in enumerate(label_list):
label_map[label] = i
tokens_a = tokenizer.tokenize(example.text_a)
tokens_b = None
if example.text_b:
tokens_b = tokenizer.tokenize(example.text_b)
if tokens_b:
# Modifies `tokens_a` and `tokens_b` in place so that the total
# length is less than the specified length.
# Account for [CLS], [SEP], [SEP] with "- 3"
self._truncate_seq_pair(tokens_a, tokens_b, max_seq_length - 3)
else:
# Account for [CLS] and [SEP] with "- 2"
if len(tokens_a) > max_seq_length - 2:
tokens_a = tokens_a[0:(max_seq_length - 2)]
# The convention in BERT is:
# (a) For sequence pairs:
# tokens: [CLS] is this jack ##son ##ville ? [SEP] no it is not . [SEP]
# type_ids: 0 0 0 0 0 0 0 0 1 1 1 1 1 1
# (b) For single sequences:
# tokens: [CLS] the dog is hairy . [SEP]
# type_ids: 0 0 0 0 0 0 0
#
# Where "type_ids" are used to indicate whether this is the first
# sequence or the second sequence. The embedding vectors for `type=0` and
# `type=1` were learned during pre-training and are added to the wordpiece
# embedding vector (and position vector). This is not *strictly* necessary
# since the [SEP] token unambiguously separates the sequences, but it makes
# it easier for the model to learn the concept of sequences.
#
# For classification tasks, the first vector (corresponding to [CLS]) is
# used as as the "sentence vector". Note that this only makes sense because
# the entire model is fine-tuned.
tokens = []
segment_ids = []
tokens.append("[CLS]")
segment_ids.append(0)
for token in tokens_a:
tokens.append(token)
segment_ids.append(0)
tokens.append("[SEP]")
segment_ids.append(0)
if tokens_b:
for token in tokens_b:
tokens.append(token)
segment_ids.append(1)
tokens.append("[SEP]")
segment_ids.append(1)
input_ids = tokenizer.convert_tokens_to_ids(tokens)
# The mask has 1 for real tokens and 0 for padding tokens. Only real
# tokens are attended to.
input_mask = [1] * len(input_ids)
# Zero-pad up to the sequence length.
while len(input_ids) < max_seq_length:
input_ids.append(0)
input_mask.append(0)
segment_ids.append(0)
assert len(input_ids) == max_seq_length
assert len(input_mask) == max_seq_length
assert len(segment_ids) == max_seq_length
label_id = label_map[example.label]
if ex_index < 5 and self.mode!="test":
tf.logging.info("*** Example ***")
tf.logging.info("guid: %s" % (example.guid))
tf.logging.info("tokens: %s" % " ".join(
[tokenization.printable_text(x) for x in tokens]))
tf.logging.info("input_ids: %s" % " ".join([str(x) for x in input_ids]))
tf.logging.info("input_mask: %s" % " ".join([str(x) for x in input_mask]))
tf.logging.info("segment_ids: %s" % " ".join([str(x) for x in segment_ids]))
tf.logging.info("label: %s (id = %d)" % (example.label, label_id))
feature = InputFeatures(
input_ids=input_ids,
input_mask=input_mask,
segment_ids=segment_ids,
label_id=label_id)
yield feature
def generate_from_queue(self):
while True:
predict_examples = self.processor.get_sentence_examples(self.input_queue.get())
features = list(self.convert_examples_to_features(predict_examples, self.processor.get_labels(),
args.max_seq_len, self.tokenizer))
yield {
'input_ids': [f.input_ids for f in features],
'input_mask': [f.input_mask for f in features],
'segment_ids': [f.segment_ids for f in features],
'label_ids': [f.label_id for f in features]
}
def _truncate_seq_pair(self, tokens_a, tokens_b, max_length):
"""Truncates a sequence pair in place to the maximum length."""
# This is a simple heuristic which will always truncate the longer sequence
# one token at a time. This makes more sense than truncating an equal percent
# of tokens from each, since if one sequence is very short then each token
# that's truncated likely contains more information than a longer sequence.
while True:
total_length = len(tokens_a) + len(tokens_b)
if total_length <= max_length:
break
if len(tokens_a) > len(tokens_b):
tokens_a.pop()
else:
tokens_b.pop()
def convert_single_example(self, ex_index, example, label_list, max_seq_length, tokenizer):
"""Converts a single `InputExample` into a single `InputFeatures`."""
label_map = {}
for (i, label) in enumerate(label_list):
label_map[label] = i
tokens_a = tokenizer.tokenize(example.text_a)
tokens_b = None
if example.text_b:
tokens_b = tokenizer.tokenize(example.text_b)
if tokens_b:
# Modifies `tokens_a` and `tokens_b` in place so that the total
# length is less than the specified length.
# Account for [CLS], [SEP], [SEP] with "- 3"
self._truncate_seq_pair(tokens_a, tokens_b, max_seq_length - 3)
else:
# Account for [CLS] and [SEP] with "- 2"
if len(tokens_a) > max_seq_length - 2:
tokens_a = tokens_a[0:(max_seq_length - 2)]
# The convention in BERT is:
# (a) For sequence pairs:
# tokens: [CLS] is this jack ##son ##ville ? [SEP] no it is not . [SEP]
# type_ids: 0 0 0 0 0 0 0 0 1 1 1 1 1 1
# (b) For single sequences:
# tokens: [CLS] the dog is hairy . [SEP]
# type_ids: 0 0 0 0 0 0 0
#
# Where "type_ids" are used to indicate whether this is the first
# sequence or the second sequence. The embedding vectors for `type=0` and
# `type=1` were learned during pre-training and are added to the wordpiece
# embedding vector (and position vector). This is not *strictly* necessary
# since the [SEP] token unambiguously separates the sequences, but it makes
# it easier for the model to learn the concept of sequences.
#
# For classification tasks, the first vector (corresponding to [CLS]) is
# used as as the "sentence vector". Note that this only makes sense because
# the entire model is fine-tuned.
tokens = []
segment_ids = []
tokens.append("[CLS]")
segment_ids.append(0)
for token in tokens_a:
tokens.append(token)
segment_ids.append(0)
tokens.append("[SEP]")
segment_ids.append(0)
if tokens_b:
for token in tokens_b:
tokens.append(token)
segment_ids.append(1)
tokens.append("[SEP]")
segment_ids.append(1)
input_ids = tokenizer.convert_tokens_to_ids(tokens)
# The mask has 1 for real tokens and 0 for padding tokens. Only real
# tokens are attended to.
input_mask = [1] * len(input_ids)
# Zero-pad up to the sequence length.
while len(input_ids) < max_seq_length:
input_ids.append(0)
input_mask.append(0)
segment_ids.append(0)
assert len(input_ids) == max_seq_length
assert len(input_mask) == max_seq_length
assert len(segment_ids) == max_seq_length
label_id = label_map[example.label]
if ex_index < 5:
tf.logging.info("*** Example ***")
tf.logging.info("guid: %s" % (example.guid))
tf.logging.info("tokens: %s" % " ".join(
[tokenization.printable_text(x) for x in tokens]))
tf.logging.info("input_ids: %s" % " ".join([str(x) for x in input_ids]))
tf.logging.info("input_mask: %s" % " ".join([str(x) for x in input_mask]))
tf.logging.info("segment_ids: %s" % " ".join([str(x) for x in segment_ids]))
tf.logging.info("label: %s (id = %d)" % (example.label, label_id))
feature = InputFeatures(
input_ids=input_ids,
input_mask=input_mask,
segment_ids=segment_ids,
label_id=label_id)
return feature
def file_based_convert_examples_to_features(self, examples, label_list, max_seq_length, tokenizer, output_file):
"""Convert a set of `InputExample`s to a TFRecord file."""
writer = tf.python_io.TFRecordWriter(output_file)
for (ex_index, example) in enumerate(examples):
if ex_index % 10000 == 0:
tf.logging.info("Writing example %d of %d" % (ex_index, len(examples)))
feature = self.convert_single_example(ex_index, example, label_list,
max_seq_length, tokenizer)
def create_int_feature(values):
f = tf.train.Feature(int64_list=tf.train.Int64List(value=list(values)))
return f
features = collections.OrderedDict()
features["input_ids"] = create_int_feature(feature.input_ids)
features["input_mask"] = create_int_feature(feature.input_mask)
features["segment_ids"] = create_int_feature(feature.segment_ids)
features["label_ids"] = create_int_feature([feature.label_id])
tf_example = tf.train.Example(features=tf.train.Features(feature=features))
writer.write(tf_example.SerializeToString())
def file_based_input_fn_builder(self, input_file, seq_length, is_training, drop_remainder):
"""Creates an `input_fn` closure to be passed to TPUEstimator."""
name_to_features = {
"input_ids": tf.FixedLenFeature([seq_length], tf.int64),
"input_mask": tf.FixedLenFeature([seq_length], tf.int64),
"segment_ids": tf.FixedLenFeature([seq_length], tf.int64),
"label_ids": tf.FixedLenFeature([], tf.int64),
}
def _decode_record(record, name_to_features):
"""Decodes a record to a TensorFlow example."""
example = tf.parse_single_example(record, name_to_features)
# tf.Example only supports tf.int64, but the TPU only supports tf.int32.
# So cast all int64 to int32.
for name in list(example.keys()):
t = example[name]
if t.dtype == tf.int64:
t = tf.to_int32(t)
example[name] = t
return example
def input_fn(params):
"""The actual input function."""
batch_size = params["batch_size"]
# For training, we want a lot of parallel reading and shuffling.
# For eval, we want no shuffling and parallel reading doesn't matter.
d = tf.data.TFRecordDataset(input_file)
if is_training:
d = d.repeat()
d = d.shuffle(buffer_size=100)
d = d.apply(
tf.contrib.data.map_and_batch(
lambda record: _decode_record(record, name_to_features),
batch_size=batch_size,
drop_remainder=drop_remainder))
return d
return input_fn
def train(self):
if self.mode is None:
raise ValueError("Please set the 'mode' parameter")
bert_config = modeling.BertConfig.from_json_file(args.config_name)
if args.max_seq_len > bert_config.max_position_embeddings:
raise ValueError(
"Cannot use sequence length %d because the BERT model "
"was only trained up to sequence length %d" %
(args.max_seq_len, bert_config.max_position_embeddings))
tf.gfile.MakeDirs(args.output_dir)
label_list = self.processor.get_labels()
train_examples = self.processor.get_train_examples(args.data_dir)
num_train_steps = int(len(train_examples) / args.batch_size * args.num_train_epochs)
estimator = self.get_estimator()
train_file = os.path.join(args.output_dir, "train.tf_record")
self.file_based_convert_examples_to_features(train_examples, label_list, args.max_seq_len, self.tokenizer,
train_file)
tf.logging.info("***** Running training *****")
tf.logging.info(" Num examples = %d", len(train_examples))
tf.logging.info(" Batch size = %d", args.batch_size)
tf.logging.info(" Num steps = %d", num_train_steps)
train_input_fn = self.file_based_input_fn_builder(input_file=train_file, seq_length=args.max_seq_len,
is_training=True,
drop_remainder=True)
# early_stopping = tf.contrib.estimator.stop_if_no_decrease_hook(
# estimator,
# metric_name='loss',
# max_steps_without_decrease=10,
# min_steps=num_train_steps)
# estimator.train(input_fn=train_input_fn, hooks=[early_stopping])
estimator.train(input_fn=train_input_fn, max_steps=num_train_steps)
def eval(self):
if self.mode is None:
raise ValueError("Please set the 'mode' parameter")
eval_examples = self.processor.get_dev_examples(args.data_dir)
eval_file = os.path.join(args.output_dir, "eval.tf_record")
label_list = self.processor.get_labels()
self.file_based_convert_examples_to_features(
eval_examples, label_list, args.max_seq_len, self.tokenizer, eval_file)
tf.logging.info("***** Running evaluation *****")
tf.logging.info(" Num examples = %d", len(eval_examples))
tf.logging.info(" Batch size = %d", self.batch_size)
eval_input_fn = self.file_based_input_fn_builder(
input_file=eval_file,
seq_length=args.max_seq_len,
is_training=False,
drop_remainder=False)
estimator = self.get_estimator()
result = estimator.evaluate(input_fn=eval_input_fn, steps=None)
output_eval_file = os.path.join(args.output_dir, "eval_results.txt")
with tf.gfile.GFile(output_eval_file, "w") as writer:
tf.logging.info("***** Eval results *****")
for key in sorted(result.keys()):
tf.logging.info(" %s = %s", key, str(result[key]))
writer.write("%s = %s\n" % (key, str(result[key])))
def predict(self, sentence1, sentence2):
if self.mode is None:
raise ValueError("Please set the 'mode' parameter")
self.input_queue.put([(sentence1, sentence2)])
prediction = self.output_queue.get()
return prediction
def test(self):
if self.mode is None:
raise ValueError("Please set the 'mode' parameter")
test_examples = self.processor.get_test_examples(args.data_dir)
output_eval_file = os.path.join(args.output_dir, "test_results.txt")
with tf.gfile.GFile(output_eval_file, "w") as writer:
for sentenceItem in test_examples:
self.input_queue.put([(sentenceItem[0], sentenceItem[1])])
prediction = self.output_queue.get()
writer.write("%s,%s,%s\n" % (sentenceItem[0], sentenceItem[1],prediction[0][1]))
八、Bert 相似度 模型 使用
训练
sim = BertSim()
sim.set_mode(tf.estimator.ModeKeys.TRAIN)
sim.train()
验证
sim = BertSim()
sim.set_mode(tf.estimator.ModeKeys.EVAL)
sim.eval()
测试
sim = BertSim()
sim.set_mode("test")
sim.test()
预测
sim = BertSim()
sim.set_mode(tf.estimator.ModeKeys.PREDICT)
while True:
sentence1 = input('sentence1: ')
sentence2 = input('sentence2: ')
import time
s = time.time()
predict = sim.predict(sentence1, sentence2)
print(time.time() - s)
print(f'similarity：{predict[0][1]}')
九、总结
本章 主要介绍了 利用 Bert 生成 句向量，代码比较简单。
【关于 Bert 源码解析 之 主体篇 】 那些的你不知道的事
【关于 Bert 源码解析 之 预训练篇 】 那些的你不知道的事
【关于 Bert 源码解析 之 微调篇 】 那些的你不知道的事
【关于 Bert 源码解析IV 之 句向量生成篇 】 那些的你不知道的事
【关于 Bert 源码解析V 之 文本相似度篇 】 那些的你不知道的事【本章】
分模块 进行解读。
参考资料
【【关于Bert】 那些的你不知道的事】
【Bert】论文
【Bert】源码
