# Copyright 2021 The Fairseq Authors and The HuggingFace Inc. team. All rights reserved.
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# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
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# http://www.apache.org/licenses/LICENSE-2.0
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"""Tokenization classes for M2M100."""
import json
from contextlib import contextmanager
from pathlib import Path
from shutil import copyfile
from typing import Dict, List, Optional, Tuple, Union
import sentencepiece
from ...tokenization_utils import BatchEncoding, PreTrainedTokenizer
from ...utils import logging
logger = logging.get_logger(__name__)
SPIECE_UNDERLINE = "▁"
VOCAB_FILES_NAMES = {
"vocab_file": "vocab.json",
"spm_file": "sentencepiece.bpe.model",
"tokenizer_config_file": "tokenizer_config.json",
}
PRETRAINED_VOCAB_FILES_MAP = {
"vocab_file": {
"facebook/m2m100_418M": "https://huggingface.co/facebook/m2m100_418M/resolve/main/vocab.json",
"facebook/m2m100_1.2B": "https://huggingface.co/facebook/m2m100_1.2B/resolve/main/vocab.json",
},
"spm_file": {
"facebook/m2m100_418M": "https://huggingface.co/facebook/m2m100_418M/resolve/main/sentencepiece.bpe.model",
"facebook/m2m100_1.2B": "https://huggingface.co/facebook/m2m100_1.2B/resolve/main/sentencepiece.bpe.model",
},
"tokenizer_config_file": {
"facebook/m2m100_418M": "https://huggingface.co/facebook/m2m100_418M/resolve/main/tokenizer_config.json",
"facebook/m2m100_1.2B": "https://huggingface.co/facebook/m2m100_1.2B/resolve/main/tokenizer_config.json",
},
}
PRETRAINED_POSITIONAL_EMBEDDINGS_SIZES = {
"facebook/m2m100_418M": 1024,
}
# fmt: off
FAIRSEQ_LANGUAGE_CODES = ["af", "am", "ar", "ast", "az", "ba", "be", "bg", "bn", "br", "bs", "ca", "ceb", "cs", "cy", "da", "de", "el", "en", "es", "et", "fa", "ff", "fi", "fr", "fy", "ga", "gd", "gl", "gu", "ha", "he", "hi", "hr", "ht", "hu", "hy", "id", "ig", "ilo", "is", "it", "ja", "jv", "ka", "kk", "km", "kn", "ko", "lb", "lg", "ln", "lo", "lt", "lv", "mg", "mk", "ml", "mn", "mr", "ms", "my", "ne", "nl", "no", "ns", "oc", "or", "pa", "pl", "ps", "pt", "ro", "ru", "sd", "si", "sk", "sl", "so", "sq", "sr", "ss", "su", "sv", "sw", "ta", "th", "tl", "tn", "tr", "uk", "ur", "uz", "vi", "wo", "xh", "yi", "yo", "zh", "zu"]
# fmt: on
[docs]class M2M100Tokenizer(PreTrainedTokenizer):
"""
Construct an M2M100 tokenizer. Based on `SentencePiece <https://github.com/google/sentencepiece>`__.
This tokenizer inherits from :class:`~transformers.PreTrainedTokenizer` which contains most of the main methods.
Users should refer to this superclass for more information regarding those methods.
Args:
vocab_file (:obj:`str`):
Path to the vocabulary file.
spm_file (:obj:`str`):
Path to `SentencePiece <https://github.com/google/sentencepiece>`__ file (generally has a .spm extension)
that contains the vocabulary.
src_lang (:obj:`str`, `optional`):
A string representing the source language.
tgt_lang (:obj:`str`, `optional`):
A string representing the target language.
eos_token (:obj:`str`, `optional`, defaults to :obj:`"</s>"`):
The end of sequence token.
sep_token (:obj:`str`, `optional`, defaults to :obj:`"</s>"`):
The separator token, which is used when building a sequence from multiple sequences, e.g. two sequences for
sequence classification or for a text and a question for question answering. It is also used as the last
token of a sequence built with special tokens.
unk_token (:obj:`str`, `optional`, defaults to :obj:`"<unk>"`):
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.
pad_token (:obj:`str`, `optional`, defaults to :obj:`"<pad>"`):
The token used for padding, for example when batching sequences of different lengths.
Examples::
>>> from transformers import M2M100Tokenizer
>>> tokenizer = M2M100Tokenizer.from_pretrained("facebook/m2m100_418M, src_lang="en", tgt_lang="ro")
>>> src_text = " UN Chief Says There Is No Military Solution in Syria"
>>> tgt_text = "Şeful ONU declară că nu există o soluţie militară în Siria"
>>> model_inputs = tokenizer(src_text, return_tensors="pt")
>>> with tokenizer.as_target_tokenizer():
... labels = tokenizer(tgt_text, return_tensors="pt").input_ids
>>> # model(**model_inputs, labels=labels) should work
"""
vocab_files_names = VOCAB_FILES_NAMES
max_model_input_sizes = PRETRAINED_POSITIONAL_EMBEDDINGS_SIZES
pretrained_vocab_files_map = PRETRAINED_VOCAB_FILES_MAP
model_input_names = ["input_ids", "attention_mask"]
prefix_tokens: List[int] = []
suffix_tokens: List[int] = []
def __init__(
self,
vocab_file,
spm_file,
src_lang=None,
tgt_lang=None,
bos_token="<s>",
eos_token="</s>",
sep_token="</s>",
pad_token="<pad>",
unk_token="<unk>",
**kwargs,
):
super().__init__(
src_lang=src_lang,
tgt_lang=tgt_lang,
bos_token=bos_token,
eos_token=eos_token,
sep_token=sep_token,
unk_token=unk_token,
pad_token=pad_token,
**kwargs,
)
self.vocab_file = vocab_file
self.encoder = load_json(vocab_file)
self.decoder = {v: k for k, v in self.encoder.items()}
self.spm_file = spm_file
self.sp_model = load_spm(spm_file)
self.encoder_size = len(self.encoder)
self.lang_code_to_token = {lang_code: f"__{lang_code}__" for lang_code in FAIRSEQ_LANGUAGE_CODES}
self.lang_token_to_id = {
self.get_lang_token(lang_code): self.encoder_size + i for i, lang_code in enumerate(FAIRSEQ_LANGUAGE_CODES)
}
self.lang_code_to_id = {lang_code: self.encoder_size + i for i, lang_code in enumerate(FAIRSEQ_LANGUAGE_CODES)}
self.id_to_lang_token = {v: k for k, v in self.lang_token_to_id.items()}
self._additional_special_tokens = list(self.lang_token_to_id.keys())
self._src_lang = src_lang if src_lang is not None else "en"
self.tgt_lang = tgt_lang
self.cur_lang_id = self.get_lang_id(self._src_lang)
self.set_src_lang_special_tokens(self._src_lang)
self.num_madeup_words = 8
@property
def vocab_size(self) -> int:
return len(self.encoder) + len(self.lang_token_to_id) + self.num_madeup_words
@property
def src_lang(self) -> str:
return self._src_lang
@src_lang.setter
def src_lang(self, new_src_lang: str) -> None:
self._src_lang = new_src_lang
self.set_src_lang_special_tokens(self._src_lang)
def _tokenize(self, text: str) -> List[str]:
return self.sp_model.EncodeAsPieces(text)
def _convert_token_to_id(self, token):
if token in self.lang_token_to_id:
return self.lang_token_to_id[token]
return self.encoder.get(token, self.encoder[self.unk_token])
def _convert_id_to_token(self, index: int) -> str:
"""Converts an index (integer) in a token (str) using the decoder."""
if index in self.id_to_lang_token:
return self.id_to_lang_token[index]
return self.decoder.get(index, self.unk_token)
def convert_tokens_to_string(self, tokens: List[str]) -> str:
"""Converts a sequence of tokens (strings for sub-words) in a single string."""
out_string = "".join(tokens).replace(SPIECE_UNDERLINE, " ").strip()
return out_string
[docs] 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 (:obj:`List[int]`):
List of IDs.
token_ids_1 (:obj:`List[int]`, `optional`):
Optional second list of IDs for sequence pairs.
already_has_special_tokens (:obj:`bool`, `optional`, defaults to :obj:`False`):
Whether or not the token list is already formatted with special tokens for the model.
Returns:
:obj:`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:
if token_ids_1 is not None:
raise ValueError(
"You should not supply a second sequence if the provided sequence of "
"ids is already formatted with special tokens for the model."
)
return list(map(lambda x: 1 if x in [self.sep_token_id, self.cls_token_id] else 0, token_ids_0))
prefix_ones = [1] * len(self.prefix_tokens)
suffix_ones = [1] * len(self.suffix_tokens)
if token_ids_1 is None:
return prefix_ones + ([0] * len(token_ids_0)) + suffix_ones
return prefix_ones + ([0] * len(token_ids_0)) + ([0] * len(token_ids_1)) + suffix_ones
def get_vocab(self) -> Dict:
vocab = self.encoder.copy()
vocab.update(self.added_tokens_encoder)
return vocab
def __getstate__(self) -> Dict:
state = self.__dict__.copy()
state["sp_model"] = None
return state
def __setstate__(self, d: Dict) -> None:
self.__dict__ = d
self.sp_model = load_spm(self.spm_file)
[docs] def save_vocabulary(self, save_directory: str, filename_prefix: Optional[str] = None) -> Tuple[str]:
save_dir = Path(save_directory)
assert save_dir.is_dir(), f"{save_directory} should be a directory"
vocab_save_path = save_dir / (
(filename_prefix + "-" if filename_prefix else "") + self.vocab_files_names["vocab_file"]
)
spm_save_path = save_dir / (
(filename_prefix + "-" if filename_prefix else "") + self.vocab_files_names["spm_file"]
)
save_json(self.encoder, vocab_save_path)
if not spm_save_path.exists():
copyfile(self.spm_file, spm_save_path)
return (str(vocab_save_path), str(spm_save_path))
def prepare_seq2seq_batch(
self,
src_texts: List[str],
src_lang: str = "en",
tgt_texts: Optional[List[str]] = None,
tgt_lang: str = "ro",
**kwargs,
) -> BatchEncoding:
self.src_lang = src_lang
self.tgt_lang = tgt_lang
self.set_src_lang_special_tokens(self.src_lang)
return super().prepare_seq2seq_batch(src_texts, tgt_texts, **kwargs)
@contextmanager
def as_target_tokenizer(self):
"""
Temporarily sets the tokenizer for encoding the targets. Useful for tokenizer associated to
sequence-to-sequence models that need a slightly different processing for the labels.
"""
self.set_tgt_lang_special_tokens(self.tgt_lang)
yield
self.set_src_lang_special_tokens(self.src_lang)
def set_src_lang_special_tokens(self, src_lang: str) -> None:
"""Reset the special tokens to the source lang setting. No prefix and suffix=[eos, src_lang_code]."""
lang_token = self.get_lang_token(src_lang)
self.cur_lang_id = self.lang_token_to_id[lang_token]
self.prefix_tokens = [self.cur_lang_id]
self.suffix_tokens = [self.eos_token_id]
def set_tgt_lang_special_tokens(self, tgt_lang: str) -> None:
"""Reset the special tokens to the target language setting. No prefix and suffix=[eos, tgt_lang_code]."""
lang_token = self.get_lang_token(tgt_lang)
self.cur_lang_id = self.lang_token_to_id[lang_token]
self.prefix_tokens = [self.cur_lang_id]
self.suffix_tokens = [self.eos_token_id]
def get_lang_token(self, lang: str) -> str:
return self.lang_code_to_token[lang]
def get_lang_id(self, lang: str) -> int:
lang_token = self.get_lang_token(lang)
return self.lang_token_to_id[lang_token]
def load_spm(path: str) -> sentencepiece.SentencePieceProcessor:
spm = sentencepiece.SentencePieceProcessor()
spm.Load(str(path))
return spm
def load_json(path: str) -> Union[Dict, List]:
with open(path, "r") as f:
return json.load(f)
def save_json(data, path: str) -> None:
with open(path, "w") as f:
json.dump(data, f, indent=2)