tokenization_plbart.py 18 KB

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  1. # coding=utf-8
  2. # Copyright 2022, UCLA NLP, The Facebook AI Research Team Authors and The HuggingFace Inc. team.
  3. #
  4. # Licensed under the Apache License, Version 2.0 (the "License");
  5. # you may not use this file except in compliance with the License.
  6. # You may obtain a copy of the License at
  7. #
  8. # http://www.apache.org/licenses/LICENSE-2.0
  9. #
  10. # Unless required by applicable law or agreed to in writing, software
  11. # distributed under the License is distributed on an "AS IS" BASIS,
  12. # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13. # See the License for the specific language governing permissions and
  14. # limitations under the License.
  15. import os
  16. from shutil import copyfile
  17. from typing import Any, Optional
  18. import sentencepiece as spm
  19. from ...tokenization_utils import AddedToken, BatchEncoding, PreTrainedTokenizer
  20. from ...utils import logging
  21. from ...utils.import_utils import requires
  22. logger = logging.get_logger(__name__)
  23. SPIECE_UNDERLINE = "▁"
  24. VOCAB_FILES_NAMES = {"vocab_file": "sentencepiece.bpe.model", "tokenizer_file": "tokenizer.json"}
  25. FAIRSEQ_LANGUAGE_CODES = {
  26. "base": ["__java__", "__python__", "__en_XX__"],
  27. "multi": ["__java__", "__python__", "__en_XX__", "__javascript__", "__php__", "__ruby__", "__go__"],
  28. }
  29. FAIRSEQ_LANGUAGE_CODES_MAP = {
  30. "java": "__java__",
  31. "python": "__python__",
  32. "en_XX": "__en_XX__",
  33. "javascript": "__javascript__",
  34. "php": "__php__",
  35. "ruby": "__ruby__",
  36. "go": "__go__",
  37. }
  38. @requires(backends=("sentencepiece",))
  39. class PLBartTokenizer(PreTrainedTokenizer):
  40. """
  41. Construct an PLBART tokenizer.
  42. Adapted from [`RobertaTokenizer`] and [`XLNetTokenizer`]. Based on
  43. [SentencePiece](https://github.com/google/sentencepiece).
  44. The tokenization method is `<tokens> <eos> <language code>` for source language documents, and `<language code>
  45. <tokens> <eos>` for target language documents.
  46. Args:
  47. vocab_file (`str`):
  48. Path to the vocabulary file.
  49. src_lang (`str`, *optional*):
  50. A string representing the source language.
  51. tgt_lang (`str`, *optional*):
  52. A string representing the target language.
  53. bos_token (`str`, *optional*, defaults to `"<s>"`):
  54. The start of sequence token.
  55. eos_token (`str`, *optional*, defaults to `"</s>"`):
  56. The end of sequence token.
  57. sep_token (`str`, *optional*, defaults to `"</s>"`):
  58. The separator token, which is used when building a sequence from multiple sequences, e.g. two sequences for
  59. sequence classification or for a text and a question for question answering. It is also used as the last
  60. token of a sequence built with special tokens.
  61. cls_token (`str`, *optional*, defaults to `"<s>"`):
  62. The cls token, which is a special token used as the first token for all tasks.
  63. unk_token (`str`, *optional*, defaults to `"<unk>"`):
  64. The unknown token. A token that is not in the vocabulary cannot be converted to an ID and is set to be this
  65. token instead.
  66. pad_token (`str`, *optional*, defaults to `"<pad>"`):
  67. The token used for padding, for example when batching sequences of different lengths.
  68. mask_token(`str`, *optional*, defaults to `"<mask>"`):
  69. The token used for masking values. This is the token used when training this model with masking tasks. This
  70. is only used in the `"base"` tokenizer type. For `"multi"` tokenizer, masking is never done for the
  71. downstream tasks.
  72. language_codes (`str`, *optional*, defaults to `"base"`):
  73. What language codes to use. Should be one of `"base"` or `"multi"`.
  74. sp_model_kwargs (`dict`, *optional*):
  75. Will be passed to the `SentencePieceProcessor.__init__()` method. The [Python wrapper for
  76. SentencePiece](https://github.com/google/sentencepiece/tree/master/python) can be used, among other things,
  77. to set:
  78. - `enable_sampling`: Enable subword regularization.
  79. - `nbest_size`: Sampling parameters for unigram. Invalid for BPE-Dropout.
  80. - `nbest_size = {0,1}`: No sampling is performed.
  81. - `nbest_size > 1`: samples from the nbest_size results.
  82. - `nbest_size < 0`: assuming that nbest_size is infinite and samples from the all hypothesis (lattice)
  83. using forward-filtering-and-backward-sampling algorithm.
  84. - `alpha`: Smoothing parameter for unigram sampling, and dropout probability of merge operations for
  85. BPE-dropout.
  86. Examples:
  87. ```python
  88. >>> from transformers import PLBartTokenizer
  89. >>> tokenizer = PLBartTokenizer.from_pretrained("uclanlp/plbart-python-en_XX", src_lang="python", tgt_lang="en_XX")
  90. >>> example_python_phrase = "def maximum(a,b,c):NEW_LINE_INDENTreturn max([a,b,c])"
  91. >>> expected_translation_english = "Returns the maximum value of a b c."
  92. >>> inputs = tokenizer(example_python_phrase, text_target=expected_translation_english, return_tensors="pt")
  93. ```"""
  94. vocab_files_names = VOCAB_FILES_NAMES
  95. model_input_names = ["input_ids", "attention_mask"]
  96. prefix_tokens: list[int] = []
  97. suffix_tokens: list[int] = []
  98. def __init__(
  99. self,
  100. vocab_file,
  101. bos_token="<s>",
  102. eos_token="</s>",
  103. sep_token="</s>",
  104. cls_token="<s>",
  105. unk_token="<unk>",
  106. pad_token="<pad>",
  107. mask_token="<mask>",
  108. language_codes="base",
  109. tokenizer_file=None,
  110. src_lang=None,
  111. tgt_lang=None,
  112. sp_model_kwargs: Optional[dict[str, Any]] = None,
  113. additional_special_tokens=None,
  114. clean_up_tokenization_spaces=True,
  115. **kwargs,
  116. ):
  117. # Mask token behave like a normal word, i.e. include the space before it
  118. mask_token = AddedToken(mask_token, lstrip=True, rstrip=False) if isinstance(mask_token, str) else mask_token
  119. self.sp_model_kwargs = {} if sp_model_kwargs is None else sp_model_kwargs
  120. src_lang = self._convert_lang_code_special_format(src_lang)
  121. tgt_lang = self._convert_lang_code_special_format(tgt_lang)
  122. self.sp_model = spm.SentencePieceProcessor(**self.sp_model_kwargs)
  123. self.sp_model.Load(str(vocab_file))
  124. self.vocab_file = vocab_file
  125. self.language_codes = language_codes
  126. fairseq_language_codes = FAIRSEQ_LANGUAGE_CODES[self.language_codes]
  127. # Original fairseq vocab and spm vocab must be "aligned":
  128. # Vocab | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9
  129. # -------- | ------- | ------- | ------ | ------- | --- | --- | --- | ----- | ----- | ----
  130. # fairseq | '<s>' | '<pad>' | '</s>' | '<unk>' | ',' | '.' | '▁' | 's' | '▁de' | '-'
  131. # spm | '<unk>' | '<s>' | '</s>' | ',' | '.' | '▁' | 's' | '▁de' | '-' | '▁a'
  132. # Mimic fairseq token-to-id alignment for the first 4 token
  133. self.fairseq_tokens_to_ids = {"<s>": 0, "<pad>": 1, "</s>": 2, "<unk>": 3}
  134. # The first "real" token "," has position 4 in the original fairseq vocab and position 3 in the spm vocab
  135. self.fairseq_offset = 1
  136. self.sp_model_size = len(self.sp_model)
  137. self.lang_code_to_id = {
  138. code: self.sp_model_size + i + self.fairseq_offset for i, code in enumerate(fairseq_language_codes)
  139. }
  140. self.id_to_lang_code = {v: k for k, v in self.lang_code_to_id.items()}
  141. if self.language_codes == "base":
  142. self.fairseq_tokens_to_ids["<mask>"] = len(self.sp_model) + len(self.lang_code_to_id) + self.fairseq_offset
  143. self.fairseq_tokens_to_ids.update(self.lang_code_to_id)
  144. self.fairseq_ids_to_tokens = {v: k for k, v in self.fairseq_tokens_to_ids.items()}
  145. _additional_special_tokens = list(self.lang_code_to_id.keys())
  146. if additional_special_tokens is not None:
  147. # Only add those special tokens if they are not already there.
  148. _additional_special_tokens.extend(
  149. [t for t in additional_special_tokens if t not in _additional_special_tokens]
  150. )
  151. if self.language_codes == "base":
  152. self._src_lang = src_lang
  153. self.cur_lang_code_id = (
  154. self.lang_code_to_id[self._src_lang] if self._src_lang is not None else self._src_lang
  155. )
  156. else:
  157. self._src_lang = src_lang if src_lang is not None else "__en_XX__"
  158. self.cur_lang_code_id = self.lang_code_to_id[self._src_lang]
  159. super().__init__(
  160. bos_token=bos_token,
  161. eos_token=eos_token,
  162. unk_token=unk_token,
  163. sep_token=sep_token,
  164. cls_token=cls_token,
  165. pad_token=pad_token,
  166. mask_token=mask_token,
  167. language_codes=language_codes,
  168. tokenizer_file=tokenizer_file,
  169. src_lang=src_lang,
  170. tgt_lang=tgt_lang,
  171. additional_special_tokens=_additional_special_tokens,
  172. sp_model_kwargs=self.sp_model_kwargs,
  173. clean_up_tokenization_spaces=clean_up_tokenization_spaces,
  174. **kwargs,
  175. )
  176. self.tgt_lang = tgt_lang
  177. self.set_src_lang_special_tokens(self._src_lang)
  178. def __getstate__(self):
  179. state = self.__dict__.copy()
  180. state["sp_model"] = None
  181. state["sp_model_proto"] = self.sp_model.serialized_model_proto()
  182. return state
  183. def __setstate__(self, d):
  184. self.__dict__ = d
  185. # for backward compatibility
  186. if not hasattr(self, "sp_model_kwargs"):
  187. self.sp_model_kwargs = {}
  188. self.sp_model = spm.SentencePieceProcessor(**self.sp_model_kwargs)
  189. self.sp_model.LoadFromSerializedProto(self.sp_model_proto)
  190. @property
  191. def vocab_size(self):
  192. if self.language_codes == "base":
  193. return (
  194. len(self.sp_model) + len(self.lang_code_to_id) + self.fairseq_offset + 1
  195. ) # Plus 1 for the mask token
  196. else:
  197. return len(self.sp_model) + len(self.lang_code_to_id) + self.fairseq_offset
  198. @property
  199. def src_lang(self) -> str:
  200. return self._src_lang
  201. @src_lang.setter
  202. def src_lang(self, new_src_lang: str) -> None:
  203. new_src_lang = self._convert_lang_code_special_format(new_src_lang)
  204. self._src_lang = new_src_lang
  205. self.set_src_lang_special_tokens(self._src_lang)
  206. def get_special_tokens_mask(
  207. self, token_ids_0: list[int], token_ids_1: Optional[list[int]] = None, already_has_special_tokens: bool = False
  208. ) -> list[int]:
  209. """
  210. Retrieve sequence ids from a token list that has no special tokens added. This method is called when adding
  211. special tokens using the tokenizer `prepare_for_model` method.
  212. Args:
  213. token_ids_0 (`list[int]`):
  214. List of IDs.
  215. token_ids_1 (`list[int]`, *optional*):
  216. Optional second list of IDs for sequence pairs.
  217. already_has_special_tokens (`bool`, *optional*, defaults to `False`):
  218. Whether or not the token list is already formatted with special tokens for the model.
  219. Returns:
  220. `list[int]`: A list of integers in the range [0, 1]: 1 for a special token, 0 for a sequence token.
  221. """
  222. if already_has_special_tokens:
  223. return super().get_special_tokens_mask(
  224. token_ids_0=token_ids_0, token_ids_1=token_ids_1, already_has_special_tokens=True
  225. )
  226. prefix_ones = [1] * len(self.prefix_tokens)
  227. suffix_ones = [1] * len(self.suffix_tokens)
  228. if token_ids_1 is None:
  229. return prefix_ones + ([0] * len(token_ids_0)) + suffix_ones
  230. return prefix_ones + ([0] * len(token_ids_0)) + ([0] * len(token_ids_1)) + suffix_ones
  231. def build_inputs_with_special_tokens(
  232. self, token_ids_0: list[int], token_ids_1: Optional[list[int]] = None
  233. ) -> list[int]:
  234. """
  235. Build model inputs from a sequence or a pair of sequence for sequence classification tasks by concatenating and
  236. adding special tokens. An PLBART sequence has the following format, where `X` represents the sequence:
  237. - `input_ids` (for encoder) `X [eos, src_lang_code]`
  238. - `decoder_input_ids`: (for decoder) `X [eos, tgt_lang_code]`
  239. BOS is never used. Pairs of sequences are not the expected use case, but they will be handled without a
  240. separator.
  241. Args:
  242. token_ids_0 (`list[int]`):
  243. List of IDs to which the special tokens will be added.
  244. token_ids_1 (`list[int]`, *optional*):
  245. Optional second list of IDs for sequence pairs.
  246. Returns:
  247. `list[int]`: List of [input IDs](../glossary#input-ids) with the appropriate special tokens.
  248. """
  249. if token_ids_1 is None:
  250. return self.prefix_tokens + token_ids_0 + self.suffix_tokens
  251. # We don't expect to process pairs, but leave the pair logic for API consistency
  252. return self.prefix_tokens + token_ids_0 + token_ids_1 + self.suffix_tokens
  253. def create_token_type_ids_from_sequences(
  254. self, token_ids_0: list[int], token_ids_1: Optional[list[int]] = None
  255. ) -> list[int]:
  256. """
  257. Create a mask from the two sequences passed to be used in a sequence-pair classification task. PLBart does not
  258. make use of token type ids, therefore a list of zeros is returned.
  259. Args:
  260. token_ids_0 (`list[int]`):
  261. List of IDs.
  262. token_ids_1 (`list[int]`, *optional*):
  263. Optional second list of IDs for sequence pairs.
  264. Returns:
  265. `list[int]`: List of zeros.
  266. """
  267. sep = [self.sep_token_id]
  268. cls = [self.cls_token_id]
  269. if token_ids_1 is None:
  270. return len(cls + token_ids_0 + sep) * [0]
  271. return len(cls + token_ids_0 + sep + sep + token_ids_1 + sep) * [0]
  272. def _build_translation_inputs(
  273. self, raw_inputs, return_tensors: str, src_lang: Optional[str], tgt_lang: Optional[str], **extra_kwargs
  274. ):
  275. """Used by translation pipeline, to prepare inputs for the generate function"""
  276. if src_lang is None or tgt_lang is None:
  277. raise ValueError("Translation requires a `src_lang` and a `tgt_lang` for this model")
  278. self.src_lang = self._convert_lang_code_special_format(src_lang)
  279. self.tgt_lang = self._convert_lang_code_special_format(tgt_lang)
  280. inputs = self(raw_inputs, add_special_tokens=True, return_tensors=return_tensors, **extra_kwargs)
  281. tgt_lang_id = self.convert_tokens_to_ids(self.tgt_lang)
  282. inputs["forced_bos_token_id"] = tgt_lang_id
  283. return inputs
  284. def get_vocab(self):
  285. vocab = {self.convert_ids_to_tokens(i): i for i in range(self.vocab_size)}
  286. vocab.update(self.added_tokens_encoder)
  287. return vocab
  288. def _tokenize(self, text: str) -> list[str]:
  289. return self.sp_model.encode(text, out_type=str)
  290. def _convert_token_to_id(self, token):
  291. """Converts a token (str) in an id using the vocab."""
  292. if token in self.fairseq_tokens_to_ids:
  293. return self.fairseq_tokens_to_ids[token]
  294. spm_id = self.sp_model.PieceToId(token)
  295. # Need to return unknown token if the SP model returned 0
  296. return spm_id + self.fairseq_offset if spm_id else self.unk_token_id
  297. def _convert_id_to_token(self, index):
  298. """Converts an index (integer) in a token (str) using the vocab."""
  299. if index in self.fairseq_ids_to_tokens:
  300. return self.fairseq_ids_to_tokens[index]
  301. return self.sp_model.IdToPiece(index - self.fairseq_offset)
  302. def convert_tokens_to_string(self, tokens):
  303. """Converts a sequence of tokens (strings for sub-words) in a single string."""
  304. out_string = "".join(tokens).replace(SPIECE_UNDERLINE, " ").strip()
  305. return out_string
  306. def save_vocabulary(self, save_directory: str, filename_prefix: Optional[str] = None) -> tuple[str]:
  307. if not os.path.isdir(save_directory):
  308. logger.error(f"Vocabulary path ({save_directory}) should be a directory")
  309. return
  310. out_vocab_file = os.path.join(
  311. save_directory, (filename_prefix + "-" if filename_prefix else "") + VOCAB_FILES_NAMES["vocab_file"]
  312. )
  313. if os.path.abspath(self.vocab_file) != os.path.abspath(out_vocab_file) and os.path.isfile(self.vocab_file):
  314. copyfile(self.vocab_file, out_vocab_file)
  315. elif not os.path.isfile(self.vocab_file):
  316. with open(out_vocab_file, "wb") as fi:
  317. content_spiece_model = self.sp_model.serialized_model_proto()
  318. fi.write(content_spiece_model)
  319. return (out_vocab_file,)
  320. def prepare_seq2seq_batch(
  321. self,
  322. src_texts: list[str],
  323. src_lang: str = "en_XX",
  324. tgt_texts: Optional[list[str]] = None,
  325. tgt_lang: str = "python",
  326. **kwargs,
  327. ) -> BatchEncoding:
  328. self.src_lang = self._convert_lang_code_special_format(src_lang)
  329. self.tgt_lang = self._convert_lang_code_special_format(tgt_lang)
  330. return super().prepare_seq2seq_batch(src_texts, tgt_texts, **kwargs)
  331. def _switch_to_input_mode(self):
  332. return self.set_src_lang_special_tokens(self.src_lang)
  333. def _switch_to_target_mode(self):
  334. return self.set_tgt_lang_special_tokens(self.tgt_lang)
  335. def set_src_lang_special_tokens(self, src_lang) -> None:
  336. """Reset the special tokens to the source lang setting. No prefix and suffix=[eos, src_lang_code]."""
  337. src_lang = self._convert_lang_code_special_format(src_lang)
  338. self.cur_lang_code = self.lang_code_to_id[src_lang] if src_lang is not None else None
  339. self.prefix_tokens = []
  340. if self.cur_lang_code is not None:
  341. self.suffix_tokens = [self.eos_token_id, self.cur_lang_code]
  342. else:
  343. self.suffix_tokens = [self.eos_token_id]
  344. def set_tgt_lang_special_tokens(self, lang: str) -> None:
  345. """Reset the special tokens to the target language setting. No prefix and suffix=[eos, tgt_lang_code]."""
  346. lang = self._convert_lang_code_special_format(lang)
  347. self.cur_lang_code = self.lang_code_to_id[lang] if lang is not None else None
  348. self.prefix_tokens = []
  349. if self.cur_lang_code is not None:
  350. self.suffix_tokens = [self.eos_token_id, self.cur_lang_code]
  351. else:
  352. self.suffix_tokens = [self.eos_token_id]
  353. def _convert_lang_code_special_format(self, lang: str) -> str:
  354. """Convert Language Codes to format tokenizer uses if required"""
  355. lang = FAIRSEQ_LANGUAGE_CODES_MAP.get(lang, lang)
  356. return lang
  357. __all__ = ["PLBartTokenizer"]