# coding=utf-8 import os import re import warnings from shutil import copyfile from typing import Any, Dict, List, Optional, Tuple import sentencepiece as spm from transformers.tokenization_utils import PreTrainedTokenizer from transformers.utils import logging logger = logging.get_logger(__name__) VOCAB_FILES_NAMES = {"vocab_file": "spiece.model"} class OpenBATokenizer(PreTrainedTokenizer): vocab_files_names = VOCAB_FILES_NAMES model_input_names = ["input_ids", "attention_mask"] def __init__( self, vocab_file, eos_token="", unk_token="", pad_token="", extra_ids=100, additional_special_tokens=None, sp_model_kwargs: Optional[Dict[str, Any]] = None, **kwargs, ) -> None: # Add extra_ids to the special token list if extra_ids > 0 and additional_special_tokens is None: additional_special_tokens = [f"" for i in range(extra_ids)] elif extra_ids > 0 and additional_special_tokens is not None: # Check that we have the right number of extra_id special tokens extra_tokens = len(set(filter(lambda x: bool("extra_id" in str(x)), additional_special_tokens))) if extra_tokens != extra_ids: raise ValueError( f"Both extra_ids ({extra_ids}) and additional_special_tokens ({additional_special_tokens}) are" " provided to T5Tokenizer. In this case the additional_special_tokens must include the extra_ids" " tokens" ) self.sp_model_kwargs = {} if sp_model_kwargs is None else sp_model_kwargs super().__init__( eos_token=eos_token, unk_token=unk_token, pad_token=pad_token, extra_ids=extra_ids, additional_special_tokens=additional_special_tokens, sp_model_kwargs=self.sp_model_kwargs, **kwargs, ) self.vocab_file = vocab_file self._extra_ids = extra_ids self.sp_model = spm.SentencePieceProcessor(**self.sp_model_kwargs) self.sp_model.Load(vocab_file) @staticmethod def _eventually_correct_t5_max_length(pretrained_model_name_or_path, max_model_length, init_max_model_length): if pretrained_model_name_or_path in OpenBATokenizer.max_model_input_sizes: deprecated_max_model_length = OpenBATokenizer.max_model_input_sizes[pretrained_model_name_or_path] if init_max_model_length is not None and init_max_model_length != max_model_length: return init_max_model_length elif init_max_model_length is None: warnings.warn( "This tokenizer was incorrectly instantiated with a model max length of" f" {deprecated_max_model_length} which will be corrected in Transformers v5.\nFor now, this" " behavior is kept to avoid breaking backwards compatibility when padding/encoding with" " `truncation is True`.\n- Be aware that you SHOULD NOT rely on" f" {pretrained_model_name_or_path} automatically truncating your input to" f" {deprecated_max_model_length} when padding/encoding.\n- If you want to encode/pad to sequences" f" longer than {deprecated_max_model_length} you can either instantiate this tokenizer with" " `model_max_length` or pass `max_length` when encoding/padding.\n- To avoid this warning, please" " instantiate this tokenizer with `model_max_length` set to your preferred value.", FutureWarning, ) return max_model_length @property def vocab_size(self): return self.sp_model.get_piece_size() + self._extra_ids def get_vocab(self): vocab = {self.convert_ids_to_tokens(i): i for i in range(self.vocab_size)} vocab.update(self.added_tokens_encoder) return vocab def get_special_tokens_mask( self, token_ids_0: List[int], token_ids_1: Optional[List[int]] = None, already_has_special_tokens: bool = False ) -> List[int]: """ Retrieve sequence ids from a token list that has no special tokens added. This method is called when adding special tokens using the tokenizer `prepare_for_model` method. Args: token_ids_0 (`List[int]`): List of IDs. token_ids_1 (`List[int]`, *optional*): Optional second list of IDs for sequence pairs. already_has_special_tokens (`bool`, *optional*, defaults to `False`): Whether or not the token list is already formatted with special tokens for the model. Returns: `List[int]`: A list of integers in the range [0, 1]: 1 for a special token, 0 for a sequence token. """ if already_has_special_tokens: return super().get_special_tokens_mask( token_ids_0=token_ids_0, token_ids_1=token_ids_1, already_has_special_tokens=True ) # normal case: some special tokens if token_ids_1 is None: return ([0] * len(token_ids_0)) + [1] return ([0] * len(token_ids_0)) + [1] + ([0] * len(token_ids_1)) + [1] def get_sentinel_tokens(self): return list( set(filter(lambda x: bool(re.search(r"", x)) is not None, self.additional_special_tokens)) ) def get_sentinel_token_ids(self): return [self._convert_token_to_id(token) for token in self.get_sentinel_tokens()] def _add_eos_if_not_present(self, token_ids: List[int]) -> List[int]: """Do not add eos again if user already added it.""" if len(token_ids) > 0 and token_ids[-1] == self.eos_token_id: warnings.warn( f"This sequence already has {self.eos_token}. In future versions this behavior may lead to duplicated" " eos tokens being added." ) return token_ids else: return token_ids + [self.eos_token_id] def create_token_type_ids_from_sequences( self, token_ids_0: List[int], token_ids_1: Optional[List[int]] = None ) -> List[int]: """ Create a mask from the two sequences passed to be used in a sequence-pair classification task. T5 does not make use of token type ids, therefore a list of zeros is returned. Args: token_ids_0 (`List[int]`): List of IDs. token_ids_1 (`List[int]`, *optional*): Optional second list of IDs for sequence pairs. Returns: `List[int]`: List of zeros. """ eos = [self.eos_token_id] if token_ids_1 is None: return len(token_ids_0 + eos) * [0] return len(token_ids_0 + eos + token_ids_1 + eos) * [0] def build_inputs_with_special_tokens( self, token_ids_0: List[int], token_ids_1: Optional[List[int]] = None ) -> List[int]: """ Build model inputs from a sequence or a pair of sequence for sequence classification tasks by concatenating and adding special tokens. A sequence has the following format: - single sequence: `X ` - pair of sequences: `A B ` Args: token_ids_0 (`List[int]`): List of IDs to which the special tokens will be added. token_ids_1 (`List[int]`, *optional*): Optional second list of IDs for sequence pairs. Returns: `List[int]`: List of [input IDs](../glossary#input-ids) with the appropriate special tokens. """ token_ids_0 = self._add_eos_if_not_present(token_ids_0) if token_ids_1 is None: return token_ids_0 else: token_ids_1 = self._add_eos_if_not_present(token_ids_1) return token_ids_0 + token_ids_1 def __getstate__(self): state = self.__dict__.copy() state["sp_model"] = None return state def __setstate__(self, d): self.__dict__ = d # for backward compatibility if not hasattr(self, "sp_model_kwargs"): self.sp_model_kwargs = {} self.sp_model = spm.SentencePieceProcessor(**self.sp_model_kwargs) self.sp_model.Load(self.vocab_file) def _tokenize(self, text: str) -> List[str]: """Take as input a string and return a list of strings (tokens) for words/sub-words""" return self.sp_model.encode(text, out_type=str) def _convert_token_to_id(self, token): """Converts a token (str) in an id using the vocab.""" if token.startswith("", token) num = int(match.group(1)) return self.vocab_size - num - 1 return self.sp_model.piece_to_id(token) def _convert_id_to_token(self, index): """Converts an index (integer) in a token (str) using the vocab.""" if index < self.sp_model.get_piece_size(): token = self.sp_model.IdToPiece(index) else: token = f"" return token def convert_tokens_to_string(self, tokens): """Converts a sequence of tokens (string) in a single string.""" current_sub_tokens = [] out_string = "" prev_is_special = False for token in tokens: # make sure that special tokens are not decoded using sentencepiece model if token in self.all_special_tokens: if not prev_is_special: out_string += " " out_string += self.sp_model.decode(current_sub_tokens) + token prev_is_special = True current_sub_tokens = [] else: current_sub_tokens.append(token) prev_is_special = False out_string += self.sp_model.decode(current_sub_tokens) return out_string.strip() def save_vocabulary(self, save_directory: str, filename_prefix: Optional[str] = None) -> Tuple[str]: if not os.path.isdir(save_directory): logger.error(f"Vocabulary path ({save_directory}) should be a directory") return out_vocab_file = os.path.join( save_directory, (filename_prefix + "-" if filename_prefix else "") + VOCAB_FILES_NAMES["vocab_file"] ) if os.path.abspath(self.vocab_file) != os.path.abspath(out_vocab_file) and os.path.isfile(self.vocab_file): copyfile(self.vocab_file, out_vocab_file) elif not os.path.isfile(self.vocab_file): with open(out_vocab_file, "wb") as fi: content_spiece_model = self.sp_model.serialized_model_proto() fi.write(content_spiece_model) return (out_vocab_file,)