def tokenize_sentence(X_text_list_train, X_text_list_test, max_sent_len=800):
"""
Tokenized sentences with train data list and fits on both train + test
:param X_text_list_train:
:param X_text_list_test:
:param max_sent_len: Max sentence len to pad to, defaults to 800
:return: x_encoder, x_padded_train, x_padded_test
"""
x_encoder = StaticTokenizerEncoder(
sample=X_text_list_train, append_eos=False, tokenize=lambda x: x,
)
x_encoded_train = [x_encoder.encode(text) for text in X_text_list_train]
x_padded_train = torch.LongTensor(
pad_sequence(x_encoded_train, max_sent_len + 1)
)
x_encoded_test = [x_encoder.encode(text) for text in X_text_list_test]
x_padded_test = torch.LongTensor(pad_sequence(x_encoded_test, max_sent_len + 1))
if x_padded_train.shape[1] > x_padded_test.shape[1]:
x_padded_test = torch.cat(
(
x_padded_test,
torch.zeros(
x_padded_test.shape[0],
x_padded_train.shape[1] - x_padded_test.shape[1],
),
),
dim=1,
).type(torch.long)
return x_encoder, x_padded_train, x_padded_test
def tokenize_sentence(X_text_list_train, X_text_list_test, MAX_SENTENCE_LEN):
x_encoder = StaticTokenizerEncoder(
sample=X_text_list_train,
append_eos=False,
tokenize=lambda x: x,
)
x_encoded_train = [x_encoder.encode(text) for text in X_text_list_train]
x_padded_train = torch.LongTensor(
pad_sequence(x_encoded_train, MAX_SENTENCE_LEN + 1))
x_encoded_test = [x_encoder.encode(text) for text in X_text_list_test]
x_padded_test = torch.LongTensor(
pad_sequence(x_encoded_test, MAX_SENTENCE_LEN + 1))
if x_padded_train.shape[1] > x_padded_test.shape[1]:
x_padded_test = torch.cat(
(
x_padded_test,
torch.zeros(
x_padded_test.shape[0],
x_padded_train.shape[1] - x_padded_test.shape[1],
),
),
dim=1,
).type(torch.long)
return x_encoder, x_padded_train, x_padded_test
def tokenize_pos_tags(X_tags_train, X_tags_test):
x_postag_encoder = StaticTokenizerEncoder(
sample=X_tags_train,
append_eos=False,
tokenize=lambda x: x,
)
x_postag_encoded_train = [
x_postag_encoder.encode(text) for text in X_tags_train
]
x_postag_padded_train = torch.LongTensor(
pad_sequence(x_postag_encoded_train, MAX_SENTENCE_LEN + 1))
# x_postag_ohe_train = torch.nn.functional.one_hot(x_postag_padded_train)
x_postag_encoded_test = [
x_postag_encoder.encode(text) for text in X_tags_test
]
x_postag_padded_test = torch.LongTensor(
pad_sequence(x_postag_encoded_test, MAX_SENTENCE_LEN + 1))
if x_postag_padded_train.shape[1] > x_postag_padded_test.shape[1]:
x_postag_padded_test = torch.cat(
(
x_postag_padded_test,
torch.zeros(
x_postag_padded_test.shape[0],
x_postag_padded_train.shape[1] -
x_postag_padded_test.shape[1],
),
),
dim=1,
).type(torch.long)
# x_postag_ohe_test = torch.nn.functional.one_hot(x_postag_padded_test)
return x_postag_encoder, x_postag_padded_train, x_postag_padded_test
def generate_encodings(self, data, labels):
encoder = StaticTokenizerEncoder(data,
tokenize=lambda s: s.split(),
min_occurrences=3)
encoded_data = [encoder.encode(document) for document in data]
encoded_data = [pad_tensor(x, length=10000) for x in encoded_data]
data = {'labels': labels, 'inputs': encoded_data}
return pd.DataFrame(data=data)
def load_data(dict_fn,
data_fn,
batch_size,
start_sign,
end_sign,
checkpoint_dir,
max_length,
max_train_data_size=0):
"""
数据加载方法，主要将分词好的数据进行整理，过程中保存字典文件，方便后续其他功能
使用，方法返回处理好的dataset，steps_per_epoch，checkpoint_prefix
Args:
dict_fn: 将训练数据的字典保存，用于以后使用，路径
data_fn: 分词好的训练数据路径
batch_size: batch大小
start_sign: 开始标记
end_sign: 结束标记
checkpoint_dir: 检查点保存路径
max_length: 最大句子长度
max_train_data_size: 最大训练数据大小
Returns:
dataset: PyTorch的DataLoader
steps_per_epoch: 每轮的步数
checkpoint_prefix: 保存检查点的前缀
"""
print("训练数据读取中...")
(input_lang,
target_lang), diag_weight = read_tokenized_data(data_fn, start_sign,
end_sign,
max_train_data_size)
diag_weight = torch.tensor(diag_weight, dtype=torch.float32)
# 合并input，target用于生成统一的字典
lang = np.hstack((input_lang, target_lang))
print("读取完成，正在格式化训练数据...")
tokenizer = StaticTokenizerEncoder(sample=lang,
tokenize=lambda x: x.split())
# 将文本序列转换文token id之后，并进行填充
input_data = [
pad_tensor(tensor=tokenizer.encode(example)[:max_length],
length=max_length,
padding_index=0) for example in input_lang
]
target_data = [
pad_tensor(tensor=tokenizer.encode(example)[:max_length],
length=max_length,
padding_index=0) for example in target_lang
]
input_tensor = stack_and_pad_tensors(input_data)[0]
target_tensor = stack_and_pad_tensors(target_data)[0]
print("格式化完成，正在整理训练数据并保存字典")
word_index = {}
vocab_list = tokenizer.vocab
for i in range(tokenizer.vocab_size):
word_index[vocab_list[i]] = i
word_index[i] = vocab_list[i]
with open(dict_fn, 'w', encoding='utf-8') as file:
file.write(json.dumps(word_index, indent=4, ensure_ascii=False))
print("数据字典保存完成！")
dataset = PairDataset(input_tensor, target_tensor, diag_weight)
loader = DataLoader(dataset=dataset,
batch_size=batch_size,
shuffle=True,
num_workers=2)
steps_per_epoch = len(input_tensor) // batch_size
return loader, steps_per_epoch
class WikiDataset(Dataset):
'''
A custom dataset object that encodes a tokenized text and its labels according to the corresponding encoders
'''
def __init__(self,
json,
text_encoder=None,
label_encoder=None,
vocab=None,
mode='train'):
'''
Initialization
Arguments:
json: Json file containing the data.
Structure of json file:
e.g:
json: {'data' : [{'id': filename,
'title': title of page,
'toc': [list of items in table of contents section of wikipage],
'intro':introduction of wiki page,
'label':'positive'/'negative' flag}]
}
Labels-required only when mode = 'train'
text_encoder: encoder object that encodes tokens to their unique integer ids
label_encoder: encoder object that encodes labels to their unique integer ids
vocab: external vocabulary used to intialize the text encoder. If vocab = None, it would be generated based on tokens from the datasets provided
mode: 'train' or 'inference': in case of mode == 'inference', the dataset object skips the labels
'''
self.data = json
assert 'data' in self.data
# Define the mode in which the dataset object is to be used
self.mode = mode
# Define text encoder and vocabulary
if text_encoder:
self._text_encoder = text_encoder
self._vocab = self._text_encoder.vocab
elif vocab:
self._vocab = vocab
self._text_encoder = StaticTokenizerEncoder(self._vocab,
append_eos=False,
tokenize=self.split)
else:
self._vocab = self.create_vocab()
self._text_encoder = StaticTokenizerEncoder(self._vocab,
append_eos=False,
tokenize=self.split)
self._vocab_size = self._text_encoder.vocab_size
# Define label encoder
if self.mode == 'train':
if label_encoder:
self._label_encoder = label_encoder
else:
self._label_encoder = LabelEncoder(
[sample['label'] for sample in self.data['data']])
self._label_size = self._label_encoder.vocab_size
else:
self._label_encoder = None
self._label_size = None
def __len__(self):
'''
Size of dataset
'''
return len(self.data['data'])
def __getitem__(self, idx):
'''
Extract item corresponding to idx'th index in data
'''
item = self.data['data'][idx]
intro_enc = self._text_encoder.encode(item['intro'])
toc = item['toc']
if toc == []:
toc_enc = self._text_encoder.encode('.')
else:
toc = ' '.join(toc)
toc_enc = self._text_encoder.encode(toc)
title_enc = self._text_encoder.encode(item['title'])
if self.mode == 'train':
return title_enc, toc_enc, intro_enc, self._label_encoder.encode(
item['label']).view(-1)
else:
return title_enc, toc_enc, intro_enc
@property
def vocab_size(self):
return self._vocab_size
@property
def label_size(self):
return self._label_size
@property
def text_encoder(self):
return self._text_encoder
@property
def label_encoder(self):
return self._label_encoder
@property
def vocab(self):
return self._vocab
def create_vocab(self, remove_less_freq_words=True, threshold=1):
'''
Creates vocabulary from the dataset tokens
Returns:
List of unique tokens in dataset
'''
temp_vocab = []
for sample in self.data['data']:
temp_vocab.extend(sample['title'].split())
temp_vocab.extend(' '.join(sample['toc']).split())
temp_vocab.extend(sample['intro'].split())
vocab = []
if remove_less_freq_words:
count_dict = collections.Counter(temp_vocab)
for word in count_dict.keys():
if count_dict[word] > threshold:
vocab.append(word)
else:
vocab = sorted(list(set(temp_vocab)))
return vocab
def split(self, x):
'''
Splits the text into tokens
'''
return x.split()
def collate_fn(self, batch, padding=True):
"""
Collate function needs to be passed to the pytorch dataloader
Returns:
(title,title_lengths): tuple containing padded sequence tensor for title and sequence lengths
(toc,toc_lengths): tuple containing padded sequence tensor for table of contents and sequence lengths
(intro,intro_lengths): tuple containing padded sequence tensor for introduction and sequence lengths
labels: tensor containing labels for the batch
"""
if self.mode == 'train':
title, toc, intro, labels = zip(*batch)
labels = torch.cat(labels)
else:
title, toc, intro = zip(*batch)
if isinstance(intro, collections.Sequence):
if padding:
title, title_lengths = stack_and_pad_tensors(title)
toc, toc_lengths = stack_and_pad_tensors(toc)
intro, intro_lengths = stack_and_pad_tensors(intro)
if self.mode == 'train':
return (title,
title_lengths), (toc,
toc_lengths), (intro,
intro_lengths), labels
else:
return (title, title_lengths), (toc,
toc_lengths), (intro,
intro_lengths)
else:
return batch
@classmethod
def fromJsonFile(cls,
json_file,
text_encoder=None,
label_encoder=None,
vocab=None,
mode='train'):
'''
Read data from json file
Arguments:
json_file: string specifying location to json_file
'''
with open(json_file, 'r') as f:
json_data = json.load(f)
return cls(json_data, text_encoder, label_encoder, vocab, mode)