# coding=utf-8 # Copyright 2022 EleutherAI and the HuggingFace Inc. team. All rights reserved. # # This code is based on EleutherAI's GPT-NeoX library and the GPT-NeoX # and OPT implementations in this library. It has been modified from its # original forms to accommodate minor architectural differences compared # to GPT-NeoX and OPT used by the Meta AI team that trained the model. # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. """Tokenization classes for LLaMA.""" import os from shutil import copyfile from typing import TYPE_CHECKING, Any, Dict, List, Optional, Tuple import sentencepiece as spm from ...convert_slow_tokenizer import import_protobuf from ...tokenization_utils import AddedToken, PreTrainedTokenizer from ...utils import logging if TYPE_CHECKING: from ...tokenization_utils_base import TextInput logger = logging.get_logger(__name__) VOCAB_FILES_NAMES = {"vocab_file": "tokenizer.model"} SPIECE_UNDERLINE = "▁" B_INST, E_INST = "[INST]", "[/INST]" B_SYS, E_SYS = "<>\n", "\n<>\n\n" DEFAULT_SYSTEM_PROMPT = """You are a helpful, respectful and honest assistant. Always answer as helpfully as possible, while being safe. Your \ answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure\ that your responses are socially unbiased and positive in nature. If a question does not make any sense, or is not factually coherent, explain why instead of answering something not \ correct. If you don't know the answer to a question, please don't share false information.""" # fmt: skip class LlamaTokenizer(PreTrainedTokenizer): """ Construct a Llama tokenizer. Based on byte-level Byte-Pair-Encoding. The default padding token is unset as there is no padding token in the original model. Args: vocab_file (`str`): Path to the vocabulary file. unk_token (`str` or `tokenizers.AddedToken`, *optional*, defaults to `""`): The unknown token. A token that is not in the vocabulary cannot be converted to an ID and is set to be this token instead. bos_token (`str` or `tokenizers.AddedToken`, *optional*, defaults to `""`): The beginning of sequence token that was used during pretraining. Can be used a sequence classifier token. eos_token (`str` or `tokenizers.AddedToken`, *optional*, defaults to `""`): The end of sequence token. pad_token (`str` or `tokenizers.AddedToken`, *optional*): A special token used to make arrays of tokens the same size for batching purpose. Will then be ignored by attention mechanisms or loss computation. sp_model_kwargs (`Dict[str, Any]`, `Optional`, *optional*): Will be passed to the `SentencePieceProcessor.__init__()` method. The [Python wrapper for SentencePiece](https://github.com/google/sentencepiece/tree/master/python) can be used, among other things, to set: - `enable_sampling`: Enable subword regularization. - `nbest_size`: Sampling parameters for unigram. Invalid for BPE-Dropout. - `nbest_size = {0,1}`: No sampling is performed. - `nbest_size > 1`: samples from the nbest_size results. - `nbest_size < 0`: assuming that nbest_size is infinite and samples from the all hypothesis (lattice) using forward-filtering-and-backward-sampling algorithm. - `alpha`: Smoothing parameter for unigram sampling, and dropout probability of merge operations for BPE-dropout. add_bos_token (`bool`, *optional*, defaults to `True`): Whether or not to add an `bos_token` at the start of sequences. add_eos_token (`bool`, *optional*, defaults to `False`): Whether or not to add an `eos_token` at the end of sequences. clean_up_tokenization_spaces (`bool`, *optional*, defaults to `False`): Whether or not to cleanup spaces after decoding, cleanup consists in removing potential artifacts like extra spaces. use_default_system_prompt (`bool`, *optional*, defaults to `False`): Whether or not the default system prompt for Llama should be used. spaces_between_special_tokens (`bool`, *optional*, defaults to `False`): Whether or not to add spaces between special tokens. legacy (`bool`, *optional*): Whether or not the `legacy` behavior of the tokenizer should be used. Legacy is before the merge of #24622 and #25224 which includes fixes to properly handle tokens that appear after special tokens. Make sure to also set `from_slow` to `True`. A simple example: - `legacy=True`: ```python >>> from transformers import LlamaTokenizerFast >>> tokenizer = LlamaTokenizerFast.from_pretrained("huggyllama/llama-7b", legacy=True, from_slow=True) >>> tokenizer.encode("Hello .") # 869 is '▁.' [1, 15043, 29871, 1, 869] ``` - `legacy=False`: ```python >>> from transformers import LlamaTokenizerFast >>> tokenizer = LlamaTokenizerFast.from_pretrained("huggyllama/llama-7b", legacy=False, from_slow=True) >>> tokenizer.encode("Hello .") # 29889 is '.' [1, 15043, 29871, 1, 29889] ``` Checkout the [pull request](https://github.com/huggingface/transformers/pull/24565) for more details. add_prefix_space (`bool`, *optional*, defaults to `True`): Whether or not to add an initial space to the input. This allows to treat the leading word just as any other word. Again, this should be set with `from_slow=True` to make sure it's taken into account. """ vocab_files_names = VOCAB_FILES_NAMES model_input_names = ["input_ids", "attention_mask"] def __init__( self, vocab_file, unk_token="", bos_token="", eos_token="", pad_token=None, sp_model_kwargs: Optional[Dict[str, Any]] = None, add_bos_token=True, add_eos_token=False, clean_up_tokenization_spaces=False, use_default_system_prompt=False, spaces_between_special_tokens=False, legacy=None, add_prefix_space=True, **kwargs, ): self.sp_model_kwargs = {} if sp_model_kwargs is None else sp_model_kwargs bos_token = AddedToken(bos_token, normalized=False, special=True) if isinstance(bos_token, str) else bos_token eos_token = AddedToken(eos_token, normalized=False, special=True) if isinstance(eos_token, str) else eos_token unk_token = AddedToken(unk_token, normalized=False, special=True) if isinstance(unk_token, str) else unk_token pad_token = AddedToken(pad_token, normalized=False, special=True) if isinstance(pad_token, str) else pad_token if legacy is None: logger.warning_once( f"You are using the default legacy behaviour of the {self.__class__}. This is" " expected, and simply means that the `legacy` (previous) behavior will be used so nothing changes for you." " If you want to use the new behaviour, set `legacy=False`. This should only be set if you understand what it" " means, and thoroughly read the reason why this was added as explained in" " https://github.com/huggingface/transformers/pull/24565 - if you loaded a llama tokenizer from a GGUF file" " you can ignore this message" ) legacy = True self.legacy = legacy self.vocab_file = vocab_file self.add_bos_token = add_bos_token self.add_eos_token = add_eos_token self.use_default_system_prompt = use_default_system_prompt self.sp_model = self.get_spm_processor(kwargs.pop("from_slow", False)) self.add_prefix_space = add_prefix_space super().__init__( bos_token=bos_token, eos_token=eos_token, unk_token=unk_token, pad_token=pad_token, add_bos_token=add_bos_token, add_eos_token=add_eos_token, sp_model_kwargs=self.sp_model_kwargs, clean_up_tokenization_spaces=clean_up_tokenization_spaces, use_default_system_prompt=use_default_system_prompt, spaces_between_special_tokens=spaces_between_special_tokens, legacy=legacy, add_prefix_space=add_prefix_space, **kwargs, ) @property def unk_token_length(self): return len(self.sp_model.encode(str(self.unk_token))) # Copied from transformers.models.t5.tokenization_t5.T5Tokenizer.get_spm_processor def get_spm_processor(self, from_slow=False): tokenizer = spm.SentencePieceProcessor(**self.sp_model_kwargs) if self.legacy or from_slow: # no dependency on protobuf tokenizer.Load(self.vocab_file) return tokenizer with open(self.vocab_file, "rb") as f: sp_model = f.read() model_pb2 = import_protobuf(f"The new behaviour of {self.__class__.__name__} (with `self.legacy = False`)") model = model_pb2.ModelProto.FromString(sp_model) normalizer_spec = model_pb2.NormalizerSpec() normalizer_spec.add_dummy_prefix = False model.normalizer_spec.MergeFrom(normalizer_spec) sp_model = model.SerializeToString() tokenizer.LoadFromSerializedProto(sp_model) return tokenizer def __getstate__(self): state = self.__dict__.copy() state["sp_model"] = None state["sp_model_proto"] = self.sp_model.serialized_model_proto() return state def __setstate__(self, d): self.__dict__.update(d) self.sp_model = spm.SentencePieceProcessor(**self.sp_model_kwargs) self.sp_model.LoadFromSerializedProto(self.sp_model_proto) @property def vocab_size(self): """Returns vocab size""" return self.sp_model.get_piece_size() def get_vocab(self): """Returns vocab as a dict""" vocab = {self.convert_ids_to_tokens(i): i for i in range(self.vocab_size)} vocab.update(self.added_tokens_encoder) return vocab # Copied from transformers.models.t5.tokenization_t5.T5Tokenizer.tokenize def tokenize(self, text: "TextInput", **kwargs) -> List[str]: """ Converts a string to a list of tokens. If `self.legacy` is set to `False`, a prefix token is added unless the first token is special. """ if self.legacy or len(text) == 0: return super().tokenize(text, **kwargs) text = text.replace(SPIECE_UNDERLINE, " ") if self.add_prefix_space: text = SPIECE_UNDERLINE + text tokens = super().tokenize(text, **kwargs) if len(tokens) > 1 and tokens[0] == SPIECE_UNDERLINE and tokens[1] in self.all_special_tokens: tokens = tokens[1:] return tokens # Copied from transformers.models.t5.tokenization_t5.T5Tokenizer._tokenize def _tokenize(self, text, **kwargs): """ Returns a tokenized string. We de-activated the `add_dummy_prefix` option, thus the sentencepiece internals will always strip any SPIECE_UNDERLINE. For example: `self.sp_model.encode(f"{SPIECE_UNDERLINE}Hey", out_type = str)` will give `['H', 'e', 'y']` instead of `['▁He', 'y']`. Thus we always encode `f"{unk_token}text"` and strip the `unk_token`. Here is an example with `unk_token = ""` and `unk_token_length = 4`. `self.tokenizer.sp_model.encode(" Hey", out_type = str)[4:]`. """ if self.legacy or not text.startswith((SPIECE_UNDERLINE, " ")): return self.sp_model.encode(text, out_type=str) # 1. Encode string + prefix ex: " Hey" tokens = self.sp_model.encode(self.unk_token + text, out_type=str) # 2. Remove self.unk_token from ['<','unk','>', '▁Hey'] return tokens[self.unk_token_length :] if len(tokens) >= self.unk_token_length else tokens def _convert_token_to_id(self, token): """Converts a token (str) in an id using the vocab.""" 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.""" token = self.sp_model.IdToPiece(index) return token def convert_tokens_to_string(self, tokens): """Converts a sequence of tokens (string) in a single string.""" # since we manually add the prefix space, we have to remove it when decoding if tokens[0].startswith(SPIECE_UNDERLINE) and self.add_prefix_space: tokens[0] = tokens[0][1:] current_sub_tokens = [] out_string = "" prev_is_special = False for i, token in enumerate(tokens): # make sure that special tokens are not decoded using sentencepiece model if token in self.all_special_tokens: if not prev_is_special and i != 0 and self.legacy: out_string += " " out_string += self.sp_model.decode(current_sub_tokens) + token prev_is_special = True current_sub_tokens = [] else: if prev_is_special and i == 1 and self.add_prefix_space and not token.startswith(SPIECE_UNDERLINE): out_string += " " current_sub_tokens.append(token) prev_is_special = False out_string += self.sp_model.decode(current_sub_tokens) return out_string def save_vocabulary(self, save_directory, filename_prefix: Optional[str] = None) -> Tuple[str]: """ Save the vocabulary and special tokens file to a directory. Args: save_directory (`str`): The directory in which to save the vocabulary. Returns: `Tuple(str)`: Paths to the files saved. """ 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,) def build_inputs_with_special_tokens(self, token_ids_0, token_ids_1=None): bos_token_id = [self.bos_token_id] if self.add_bos_token else [] eos_token_id = [self.eos_token_id] if self.add_eos_token else [] output = bos_token_id + token_ids_0 + eos_token_id if token_ids_1 is not None: output = output + bos_token_id + token_ids_1 + eos_token_id return output 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 ) bos_token_id = [1] if self.add_bos_token else [] eos_token_id = [1] if self.add_eos_token else [] if token_ids_1 is None: return bos_token_id + ([0] * len(token_ids_0)) + eos_token_id return ( bos_token_id + ([0] * len(token_ids_0)) + eos_token_id + bos_token_id + ([0] * len(token_ids_1)) + 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]: """ Creates a mask from the two sequences passed to be used in a sequence-pair classification task. An ALBERT sequence pair mask has the following format: ``` 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 | first sequence | second sequence | ``` if token_ids_1 is None, only returns the first portion of the mask (0s). 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 [token type IDs](../glossary#token-type-ids) according to the given sequence(s). """ bos_token_id = [self.bos_token_id] if self.add_bos_token else [] eos_token_id = [self.eos_token_id] if self.add_eos_token else [] output = [0] * len(bos_token_id + token_ids_0 + eos_token_id) if token_ids_1 is not None: output += [1] * len(bos_token_id + token_ids_1 + eos_token_id) return output __all__ = ["LlamaTokenizer"]