def normalizer(self, proto):
list_normalizers = [
normalizers.Replace("``", '"'),
normalizers.Replace("''", '"'),
]
if not self.original_tokenizer.keep_accents:
list_normalizers.append(normalizers.NFKD())
list_normalizers.append(normalizers.StripAccents())
if self.original_tokenizer.do_lower_case:
list_normalizers.append(normalizers.Lowercase())
precompiled_charsmap = proto.normalizer_spec.precompiled_charsmap
list_normalizers.append(normalizers.Precompiled(precompiled_charsmap))
list_normalizers.append(normalizers.Replace(Regex(" {2,}"), " "))
return normalizers.Sequence(list_normalizers)
def train_tokenizer() -> Tuple[tokenizers.Tokenizer, Generator, int]:
tokenizer = tokenizers.Tokenizer(models.WordPiece(unk_token="<unk>"))
tokenizer.decoder = decoders.WordPiece()
tokenizer.normalizer = normalizers.Sequence([
normalizers.NFD(), # NFD unicode normalizer
normalizers.Lowercase(),
normalizers.StripAccents()
])
tokenizer.pre_tokenizer = tokenizers.pre_tokenizers.Sequence([
pre_tokenizers.Whitespace(),
pre_tokenizers.Digits(individual_digits=False)
])
tokenizer.post_processor = processors.TemplateProcessing(
single="$A </s>",
pair="$A </s> [SEP] <s> $B:1",
special_tokens=[("[SEP]", 1), ("<s>", 2), ("</s>", 3)])
dataset = datasets.load_dataset("wikitext",
"wikitext-103-raw-v1",
split="test")
def batch_iterator(batch_size=1000):
for i in range(0, len(dataset), batch_size):
yield dataset[i:i + batch_size]["text"]
tokenizer.train_from_iterator(
batch_iterator(),
trainer=trainers.WordPieceTrainer(
vocab_size=10000, special_tokens=["<unk>", "[SEP]", "<s>",
"</s>"]))
def generator():
for record in dataset:
if record['text'].strip() != '':
for sentence in sent_tokenizer(record['text']):
yield sentence
data = tf.data.Dataset.from_generator(generator,
output_signature=(tf.TensorSpec(
shape=(None), dtype=tf.string)))
data = data.map(tf.strings.strip,
num_parallel_calls=tf.data.experimental.AUTOTUNE)
return tokenizer, data
def train_tokenizer() -> tokenizers.Tokenizer:
tokenizer = tokenizers.Tokenizer(models.WordPiece(unk_token="<unk>"))
tokenizer.decoder = decoders.WordPiece()
tokenizer.normalizer = normalizers.Sequence([
normalizers.NFD(), # NFD unicode normalizer
normalizers.Lowercase(),
normalizers.StripAccents()
])
tokenizer.pre_tokenizer = tokenizers.pre_tokenizers.Sequence([
pre_tokenizers.Whitespace(),
pre_tokenizers.Digits(individual_digits=False)
])
tokenizer.post_processor = processors.TemplateProcessing(
single="$A </s>",
pair="$A </s> [SEP] <s> $B:1",
special_tokens=[("[SEP]", 1), ("<s>", 2), ("</s>", 3)])
# dataset = datasets.load_dataset("wikitext", "wikitext-103-raw-v1", split="train+test+validation")
dataset = datasets.load_dataset("wikitext",
"wikitext-103-raw-v1",
split="validation")
def batch_iterator(batch_size=1000):
for i in range(0, len(dataset), batch_size):
yield dataset[i:i + batch_size]["text"]
tokenizer.train_from_iterator(
batch_iterator(),
trainer=trainers.WordPieceTrainer(
vocab_size=10000, special_tokens=["<unk>", "[SEP]", "<s>",
"</s>"]))
def generator():
for record in dataset:
if record['text'].strip() != '':
yield record['text']
return tokenizer, generator
