# coding=utf-8
# Copyright 2019 The Open AI Team Authors and The HuggingFace Inc. team.
#
# 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 OpenAI GPT."""
from __future__ import (absolute_import, division, print_function,
unicode_literals)
import json
import logging
import os
import re
import sys
import unicodedata
from io import open
import sacremoses as sm
from .tokenization_utils import PreTrainedTokenizer
from .tokenization_bert import BasicTokenizer
logger = logging.getLogger(__name__)
VOCAB_FILES_NAMES = {
'vocab_file': 'vocab.json',
'merges_file': 'merges.txt',
}
PRETRAINED_VOCAB_FILES_MAP = {
'vocab_file':
{
'xlm-mlm-en-2048': "https://s3.amazonaws.com/models.huggingface.co/bert/xlm-mlm-en-2048-vocab.json",
'xlm-mlm-ende-1024': "https://s3.amazonaws.com/models.huggingface.co/bert/xlm-mlm-ende-1024-vocab.json",
'xlm-mlm-enfr-1024': "https://s3.amazonaws.com/models.huggingface.co/bert/xlm-mlm-enfr-1024-vocab.json",
'xlm-mlm-enro-1024': "https://s3.amazonaws.com/models.huggingface.co/bert/xlm-mlm-enro-1024-vocab.json",
'xlm-mlm-tlm-xnli15-1024': "https://s3.amazonaws.com/models.huggingface.co/bert/xlm-mlm-tlm-xnli15-1024-vocab.json",
'xlm-mlm-xnli15-1024': "https://s3.amazonaws.com/models.huggingface.co/bert/xlm-mlm-xnli15-1024-vocab.json",
'xlm-clm-enfr-1024': "https://s3.amazonaws.com/models.huggingface.co/bert/xlm-clm-enfr-1024-vocab.json",
'xlm-clm-ende-1024': "https://s3.amazonaws.com/models.huggingface.co/bert/xlm-clm-ende-1024-vocab.json",
'xlm-mlm-17-1280': "https://s3.amazonaws.com/models.huggingface.co/bert/xlm-mlm-17-1280-vocab.json",
'xlm-mlm-100-1280': "https://s3.amazonaws.com/models.huggingface.co/bert/xlm-mlm-100-1280-vocab.json",
},
'merges_file':
{
'xlm-mlm-en-2048': "https://s3.amazonaws.com/models.huggingface.co/bert/xlm-mlm-en-2048-merges.txt",
'xlm-mlm-ende-1024': "https://s3.amazonaws.com/models.huggingface.co/bert/xlm-mlm-ende-1024-merges.txt",
'xlm-mlm-enfr-1024': "https://s3.amazonaws.com/models.huggingface.co/bert/xlm-mlm-enfr-1024-merges.txt",
'xlm-mlm-enro-1024': "https://s3.amazonaws.com/models.huggingface.co/bert/xlm-mlm-enro-1024-merges.txt",
'xlm-mlm-tlm-xnli15-1024': "https://s3.amazonaws.com/models.huggingface.co/bert/xlm-mlm-tlm-xnli15-1024-merges.txt",
'xlm-mlm-xnli15-1024': "https://s3.amazonaws.com/models.huggingface.co/bert/xlm-mlm-xnli15-1024-merges.txt",
'xlm-clm-enfr-1024': "https://s3.amazonaws.com/models.huggingface.co/bert/xlm-mlm-enfr-1024-merges.txt",
'xlm-clm-ende-1024': "https://s3.amazonaws.com/models.huggingface.co/bert/xlm-mlm-ende-1024-merges.txt",
'xlm-mlm-17-1280': "https://s3.amazonaws.com/models.huggingface.co/bert/xlm-mlm-17-1280-merges.txt",
'xlm-mlm-100-1280': "https://s3.amazonaws.com/models.huggingface.co/bert/xlm-mlm-100-1280-merges.txt",
},
}
PRETRAINED_POSITIONAL_EMBEDDINGS_SIZES = {
'xlm-mlm-en-2048': 512,
'xlm-mlm-ende-1024': 512,
'xlm-mlm-enfr-1024': 512,
'xlm-mlm-enro-1024': 512,
'xlm-mlm-tlm-xnli15-1024': 512,
'xlm-mlm-xnli15-1024': 512,
'xlm-clm-enfr-1024': 512,
'xlm-clm-ende-1024': 512,
'xlm-mlm-17-1280': 512,
'xlm-mlm-100-1280': 512,
}
PRETRAINED_INIT_CONFIGURATION = {
'xlm-mlm-en-2048': {"do_lowercase_and_remove_accent": True},
'xlm-mlm-ende-1024': { "do_lowercase_and_remove_accent": True,
"id2lang": { "0": "de",
"1": "en"},
"lang2id": { "de": 0,
"en": 1 }},
'xlm-mlm-enfr-1024': { "do_lowercase_and_remove_accent": True,
"id2lang": { "0": "en",
"1": "fr"},
"lang2id": { "en": 0,
"fr": 1 }},
'xlm-mlm-enro-1024': { "do_lowercase_and_remove_accent": True,
"id2lang": { "0": "en",
"1": "ro"},
"lang2id": { "en": 0,
"ro": 1 }},
'xlm-mlm-tlm-xnli15-1024': { "do_lowercase_and_remove_accent": True,
"id2lang": { "0": "ar",
"1": "bg",
"2": "de",
"3": "el",
"4": "en",
"5": "es",
"6": "fr",
"7": "hi",
"8": "ru",
"9": "sw",
"10": "th",
"11": "tr",
"12": "ur",
"13": "vi",
"14": "zh"},
"lang2id": { "ar": 0,
"bg": 1,
"de": 2,
"el": 3,
"en": 4,
"es": 5,
"fr": 6,
"hi": 7,
"ru": 8,
"sw": 9,
"th": 10,
"tr": 11,
"ur": 12,
"vi": 13,
"zh": 14 }},
'xlm-mlm-xnli15-1024': { "do_lowercase_and_remove_accent": True,
"id2lang": { "0": "ar",
"1": "bg",
"2": "de",
"3": "el",
"4": "en",
"5": "es",
"6": "fr",
"7": "hi",
"8": "ru",
"9": "sw",
"10": "th",
"11": "tr",
"12": "ur",
"13": "vi",
"14": "zh"},
"lang2id": { "ar": 0,
"bg": 1,
"de": 2,
"el": 3,
"en": 4,
"es": 5,
"fr": 6,
"hi": 7,
"ru": 8,
"sw": 9,
"th": 10,
"tr": 11,
"ur": 12,
"vi": 13,
"zh": 14 }},
'xlm-clm-enfr-1024': { "do_lowercase_and_remove_accent": True,
"id2lang": { "0": "en",
"1": "fr"},
"lang2id": { "en": 0,
"fr": 1 }},
'xlm-clm-ende-1024': { "do_lowercase_and_remove_accent": True,
"id2lang": { "0": "de",
"1": "en"},
"lang2id": { "de": 0,
"en": 1 }},
'xlm-mlm-17-1280': {"do_lowercase_and_remove_accent": False,
"id2lang": {
"0": "ar",
"1": "de",
"2": "en",
"3": "es",
"4": "fr",
"5": "hi",
"6": "it",
"7": "ja",
"8": "ko",
"9": "nl",
"10": "pl",
"11": "pt",
"12": "ru",
"13": "sv",
"14": "tr",
"15": "vi",
"16": "zh"
},
"lang2id": {
"ar": 0,
"de": 1,
"en": 2,
"es": 3,
"fr": 4,
"hi": 5,
"it": 6,
"ja": 7,
"ko": 8,
"nl": 9,
"pl": 10,
"pt": 11,
"ru": 12,
"sv": 13,
"tr": 14,
"vi": 15,
"zh": 16}},
'xlm-mlm-100-1280': {"do_lowercase_and_remove_accent": False,
"id2lang": {
"0": "af",
"1": "als",
"2": "am",
"3": "an",
"4": "ang",
"5": "ar",
"6": "arz",
"7": "ast",
"8": "az",
"9": "bar",
"10": "be",
"11": "bg",
"12": "bn",
"13": "br",
"14": "bs",
"15": "ca",
"16": "ceb",
"17": "ckb",
"18": "cs",
"19": "cy",
"20": "da",
"21": "de",
"22": "el",
"23": "en",
"24": "eo",
"25": "es",
"26": "et",
"27": "eu",
"28": "fa",
"29": "fi",
"30": "fr",
"31": "fy",
"32": "ga",
"33": "gan",
"34": "gl",
"35": "gu",
"36": "he",
"37": "hi",
"38": "hr",
"39": "hu",
"40": "hy",
"41": "ia",
"42": "id",
"43": "is",
"44": "it",
"45": "ja",
"46": "jv",
"47": "ka",
"48": "kk",
"49": "kn",
"50": "ko",
"51": "ku",
"52": "la",
"53": "lb",
"54": "lt",
"55": "lv",
"56": "mk",
"57": "ml",
"58": "mn",
"59": "mr",
"60": "ms",
"61": "my",
"62": "nds",
"63": "ne",
"64": "nl",
"65": "nn",
"66": "no",
"67": "oc",
"68": "pl",
"69": "pt",
"70": "ro",
"71": "ru",
"72": "scn",
"73": "sco",
"74": "sh",
"75": "si",
"76": "simple",
"77": "sk",
"78": "sl",
"79": "sq",
"80": "sr",
"81": "sv",
"82": "sw",
"83": "ta",
"84": "te",
"85": "th",
"86": "tl",
"87": "tr",
"88": "tt",
"89": "uk",
"90": "ur",
"91": "uz",
"92": "vi",
"93": "war",
"94": "wuu",
"95": "yi",
"96": "zh",
"97": "zh_classical",
"98": "zh_min_nan",
"99": "zh_yue"
},
"lang2id": {
"af": 0,
"als": 1,
"am": 2,
"an": 3,
"ang": 4,
"ar": 5,
"arz": 6,
"ast": 7,
"az": 8,
"bar": 9,
"be": 10,
"bg": 11,
"bn": 12,
"br": 13,
"bs": 14,
"ca": 15,
"ceb": 16,
"ckb": 17,
"cs": 18,
"cy": 19,
"da": 20,
"de": 21,
"el": 22,
"en": 23,
"eo": 24,
"es": 25,
"et": 26,
"eu": 27,
"fa": 28,
"fi": 29,
"fr": 30,
"fy": 31,
"ga": 32,
"gan": 33,
"gl": 34,
"gu": 35,
"he": 36,
"hi": 37,
"hr": 38,
"hu": 39,
"hy": 40,
"ia": 41,
"id": 42,
"is": 43,
"it": 44,
"ja": 45,
"jv": 46,
"ka": 47,
"kk": 48,
"kn": 49,
"ko": 50,
"ku": 51,
"la": 52,
"lb": 53,
"lt": 54,
"lv": 55,
"mk": 56,
"ml": 57,
"mn": 58,
"mr": 59,
"ms": 60,
"my": 61,
"nds": 62,
"ne": 63,
"nl": 64,
"nn": 65,
"no": 66,
"oc": 67,
"pl": 68,
"pt": 69,
"ro": 70,
"ru": 71,
"scn": 72,
"sco": 73,
"sh": 74,
"si": 75,
"simple": 76,
"sk": 77,
"sl": 78,
"sq": 79,
"sr": 80,
"sv": 81,
"sw": 82,
"ta": 83,
"te": 84,
"th": 85,
"tl": 86,
"tr": 87,
"tt": 88,
"uk": 89,
"ur": 90,
"uz": 91,
"vi": 92,
"war": 93,
"wuu": 94,
"yi": 95,
"zh": 96,
"zh_classical": 97,
"zh_min_nan": 98,
"zh_yue": 99
}},
}
def get_pairs(word):
"""
Return set of symbol pairs in a word.
word is represented as tuple of symbols (symbols being variable-length strings)
"""
pairs = set()
prev_char = word[0]
for char in word[1:]:
pairs.add((prev_char, char))
prev_char = char
return pairs
def lowercase_and_remove_accent(text):
"""
Lowercase and strips accents from a piece of text based on
https://github.com/facebookresearch/XLM/blob/master/tools/lowercase_and_remove_accent.py
"""
text = ' '.join(text)
text = text.lower()
text = unicodedata.normalize("NFD", text)
output = []
for char in text:
cat = unicodedata.category(char)
if cat == "Mn":
continue
output.append(char)
return "".join(output).lower().split(' ')
def replace_unicode_punct(text):
'''
Port of https://github.com/moses-smt/mosesdecoder/blob/master/scripts/tokenizer/replace-unicode-punctuation.perl
'''
text = text.replace('，', ',')
text = re.sub(r'。\s*', '. ', text)
text = text.replace('、', ',')
text = text.replace('”', '"')
text = text.replace('“', '"')
text = text.replace('∶', ':')
text = text.replace('：', ':')
text = text.replace('？', '?')
text = text.replace('《', '"')
text = text.replace('》', '"')
text = text.replace('）', ')')
text = text.replace('！', '!')
text = text.replace('（', '(')
text = text.replace('；', ';')
text = text.replace('１', '"')
text = text.replace('」', '"')
text = text.replace('「', '"')
text = text.replace('０', '0')
text = text.replace('３', '3')
text = text.replace('２', '2')
text = text.replace('５', '5')
text = text.replace('６', '6')
text = text.replace('９', '9')
text = text.replace('７', '7')
text = text.replace('８', '8')
text = text.replace('４', '4')
text = re.sub(r'．\s*', '. ', text)
text = text.replace('～', '~')
text = text.replace('’', '\'')
text = text.replace('…', '...')
text = text.replace('━', '-')
text = text.replace('〈', '<')
text = text.replace('〉', '>')
text = text.replace('【', '[')
text = text.replace('】', ']')
text = text.replace('％', '%')
return text
def remove_non_printing_char(text):
'''
Port of https://github.com/moses-smt/mosesdecoder/blob/master/scripts/tokenizer/remove-non-printing-char.perl
'''
output = []
for char in text:
cat = unicodedata.category(char)
if cat.startswith('C'):
continue
output.append(char)
return "".join(output)
def romanian_preprocessing(text):
'''Sennrich's WMT16 scripts for Romanian preprocessing, used by model `xlm-mlm-enro-1024`'''
# https://github.com/rsennrich/wmt16-scripts/blob/master/preprocess/normalise-romanian.py
text = text.replace("\u015e", "\u0218").replace("\u015f", "\u0219")
text = text.replace("\u0162", "\u021a").replace("\u0163", "\u021b")
# https://github.com/rsennrich/wmt16-scripts/blob/master/preprocess/remove-diacritics.py
text = text.replace("\u0218", "S").replace("\u0219", "s") #s-comma
text = text.replace("\u021a", "T").replace("\u021b", "t") #t-comma
text = text.replace("\u0102", "A").replace("\u0103", "a")
text = text.replace("\u00C2", "A").replace("\u00E2", "a")
text = text.replace("\u00CE", "I").replace("\u00EE", "i")
return text
[docs]class XLMTokenizer(PreTrainedTokenizer):
"""
BPE tokenizer for XLM
- Moses preprocessing & tokenization for most supported languages
- Language specific tokenization for Chinese (Jieba), Japanese (KyTea) and Thai (PyThaiNLP)
- (optionally) lower case & normalize all inputs text
- argument ``special_tokens`` and function ``set_special_tokens``, can be used to add additional symbols \
(ex: "__classify__") to a vocabulary
- `lang2id` attribute maps the languages supported by the model with their ids if provided (automatically set for pretrained vocabularies)
- `id2lang` attributes does reverse mapping if provided (automatically set for pretrained vocabularies)
- `do_lowercase_and_remove_accent` controle lower casing and accent (automatically set for pretrained vocabularies)
"""
vocab_files_names = VOCAB_FILES_NAMES
pretrained_vocab_files_map = PRETRAINED_VOCAB_FILES_MAP
pretrained_init_configuration = PRETRAINED_INIT_CONFIGURATION
max_model_input_sizes = PRETRAINED_POSITIONAL_EMBEDDINGS_SIZES
def __init__(self, vocab_file, merges_file, unk_token="<unk>", bos_token="<s>",
sep_token="</s>", pad_token="<pad>", cls_token="</s>",
mask_token="<special1>", additional_special_tokens=["<special0>",
"<special1>", "<special2>", "<special3>", "<special4>", "<special5>",
"<special6>", "<special7>", "<special8>", "<special9>"],
lang2id=None, id2lang=None, do_lowercase_and_remove_accent=True,
**kwargs):
super(XLMTokenizer, self).__init__(unk_token=unk_token, bos_token=bos_token,
sep_token=sep_token, pad_token=pad_token,
cls_token=cls_token, mask_token=mask_token,
additional_special_tokens=additional_special_tokens,
**kwargs)
# cache of sm.MosesPunctNormalizer instance
self.cache_moses_punct_normalizer = dict()
# cache of sm.MosesTokenizer instance
self.cache_moses_tokenizer = dict()
self.lang_with_custom_tokenizer = set(['zh', 'th', 'ja'])
# True for current supported model (v1.2.0), False for XLM-17 & 100
self.do_lowercase_and_remove_accent = do_lowercase_and_remove_accent
self.lang2id = lang2id
self.id2lang = id2lang
if lang2id is not None and id2lang is not None:
assert len(lang2id) == len(id2lang)
self.ja_word_tokenizer = None
self.zh_word_tokenizer = None
self.encoder = json.load(open(vocab_file, encoding="utf-8"))
self.decoder = {v:k for k,v in self.encoder.items()}
merges = open(merges_file, encoding='utf-8').read().split('\n')[:-1]
merges = [tuple(merge.split()[:2]) for merge in merges]
self.bpe_ranks = dict(zip(merges, range(len(merges))))
self.cache = {}
def moses_punct_norm(self, text, lang):
if lang not in self.cache_moses_punct_normalizer:
punct_normalizer = sm.MosesPunctNormalizer(lang=lang)
self.cache_moses_punct_normalizer[lang] = punct_normalizer
else:
punct_normalizer = self.cache_moses_punct_normalizer[lang]
return punct_normalizer.normalize(text)
def moses_tokenize(self, text, lang):
if lang not in self.cache_moses_tokenizer:
moses_tokenizer = sm.MosesTokenizer(lang=lang)
self.cache_moses_tokenizer[lang] = moses_tokenizer
else:
moses_tokenizer = self.cache_moses_tokenizer[lang]
return moses_tokenizer.tokenize(text, return_str=False, escape=False)
def moses_pipeline(self, text, lang):
text = replace_unicode_punct(text)
text = self.moses_punct_norm(text, lang)
text = remove_non_printing_char(text)
return text
def ja_tokenize(self, text):
if self.ja_word_tokenizer is None:
try:
import Mykytea
self.ja_word_tokenizer = Mykytea.Mykytea('-model %s/local/share/kytea/model.bin' % os.path.expanduser('~'))
except (AttributeError, ImportError) as e:
logger.error("Make sure you install KyTea (https://github.com/neubig/kytea) and it's python wrapper (https://github.com/chezou/Mykytea-python) with the following steps")
logger.error("1. git clone git@github.com:neubig/kytea.git && cd kytea")
logger.error("2. autoreconf -i")
logger.error("3. ./configure --prefix=$HOME/local")
logger.error("4. make && make install")
logger.error("5. pip install kytea")
raise e
return list(self.ja_word_tokenizer.getWS(text))
@property
def vocab_size(self):
return len(self.encoder)
def bpe(self, token):
word = tuple(token[:-1]) + (token[-1] + '</w>',)
if token in self.cache:
return self.cache[token]
pairs = get_pairs(word)
if not pairs:
return token+'</w>'
while True:
bigram = min(pairs, key=lambda pair: self.bpe_ranks.get(pair, float('inf')))
if bigram not in self.bpe_ranks:
break
first, second = bigram
new_word = []
i = 0
while i < len(word):
try:
j = word.index(first, i)
new_word.extend(word[i:j])
i = j
except:
new_word.extend(word[i:])
break
if word[i] == first and i < len(word)-1 and word[i+1] == second:
new_word.append(first+second)
i += 2
else:
new_word.append(word[i])
i += 1
new_word = tuple(new_word)
word = new_word
if len(word) == 1:
break
else:
pairs = get_pairs(word)
word = ' '.join(word)
if word == '\n </w>':
word = '\n</w>'
self.cache[token] = word
return word
def _tokenize(self, text, lang='en', bypass_tokenizer=False):
"""
Tokenize a string given language code. For Chinese, Japanese and Thai, we use a language specific tokenizerself. Otherwise, we use Moses.
Details of tokenization:
- [sacremoses](https://github.com/alvations/sacremoses): port of Moses
- Install with `pip install sacremoses`
- [pythainlp](https://github.com/PyThaiNLP/pythainlp): Thai tokenizer
- Install with `pip install pythainlp`
- [kytea](https://github.com/chezou/Mykytea-python): Japanese tokenizer, wrapper of [KyTea](https://github.com/neubig/kytea)
- Install with the following steps:
```
git clone git@github.com:neubig/kytea.git && cd kytea
autoreconf -i
./configure --prefix=$HOME/local
make && make install
pip install kytea
```
- [jieba](https://github.com/fxsjy/jieba): Chinese tokenizer *
- Install with `pip install jieba`
\* The original XLM used [Stanford Segmenter](https://nlp.stanford.edu/software/stanford-segmenter-2018-10-16.zip).
However, the wrapper (`nltk.tokenize.stanford_segmenter`) is slow due to JVM overhead, and it will be deprecated.
Jieba is a lot faster and pip-installable. Note there is some mismatch with the Stanford Segmenter. It should be fine
if you fine-tune the model with Chinese supervisionself. If you want the same exact behaviour, use the original XLM
[preprocessing script](https://github.com/facebookresearch/XLM/tree/master/tools) to tokenize the sentence externally,
and set `bypass_tokenizer=True` to bypass the tokenizer.
Args:
- lang: ISO language code (default = 'en') (string). Languages should belong of the model supported languages. However, we don't enforce it.
- bypass_tokenizer: Allow users to preprocess and tokenize the sentences externally (default = False) (bool). If True, we only apply BPE.
Returns:
List of tokens.
"""
if lang and self.lang2id and lang not in self.lang2id:
logger.error("Supplied language code not found in lang2id mapping. Please check that your language is supported by the loaded pretrained model.")
if bypass_tokenizer:
text = text.split()
elif lang not in self.lang_with_custom_tokenizer:
text = self.moses_pipeline(text, lang=lang)
# TODO: make sure we are using `xlm-mlm-enro-1024`, since XLM-100 doesn't have this step
if lang == 'ro':
text = romanian_preprocessing(text)
text = self.moses_tokenize(text, lang=lang)
elif lang == 'th':
text = self.moses_pipeline(text, lang=lang)
try:
if 'pythainlp' not in sys.modules:
from pythainlp.tokenize import word_tokenize as th_word_tokenize
else:
th_word_tokenize = sys.modules['pythainlp'].word_tokenize
except (AttributeError, ImportError) as e:
logger.error("Make sure you install PyThaiNLP (https://github.com/PyThaiNLP/pythainlp) with the following steps")
logger.error("1. pip install pythainlp")
raise e
text = th_word_tokenize(text)
elif lang == 'zh':
try:
if 'jieba' not in sys.modules:
import jieba
else:
jieba = sys.modules['jieba']
except (AttributeError, ImportError) as e:
logger.error("Make sure you install Jieba (https://github.com/fxsjy/jieba) with the following steps")
logger.error("1. pip install jieba")
raise e
text = ' '.join(jieba.cut(text))
text = self.moses_pipeline(text, lang=lang)
text = text.split()
elif lang == 'ja':
text = self.moses_pipeline(text, lang=lang)
text = self.ja_tokenize(text)
else:
raise ValueError('It should not reach here')
if self.do_lowercase_and_remove_accent and not bypass_tokenizer:
text = lowercase_and_remove_accent(text)
split_tokens = []
for token in text:
if token:
split_tokens.extend([t for t in self.bpe(token).split(' ')])
return split_tokens
def _convert_token_to_id(self, token):
""" Converts a token (str/unicode) in an id using the vocab. """
return self.encoder.get(token, self.encoder.get(self.unk_token))
def _convert_id_to_token(self, index):
"""Converts an index (integer) in a token (string/unicode) using the vocab."""
return self.decoder.get(index, self.unk_token)
[docs] def convert_tokens_to_string(self, tokens):
""" Converts a sequence of tokens (string) in a single string. """
out_string = ''.join(tokens).replace('</w>', ' ').strip()
return out_string
[docs] def get_special_tokens_mask(self, token_ids_0, token_ids_1=None, already_has_special_tokens=False):
"""
Retrieves 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`` or ``encode_plus`` methods.
Args:
token_ids_0: list of ids (must not contain special tokens)
token_ids_1: Optional list of ids (must not contain special tokens), necessary when fetching sequence ids
for sequence pairs
already_has_special_tokens: (default False) Set to True if the token list is already formated with
special tokens for the model
Returns:
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 formated 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))
if token_ids_1 is not None:
return [1] + ([0] * len(token_ids_0)) + [1] + ([0] * len(token_ids_1)) + [1]
return [1] + ([0] * len(token_ids_0)) + [1]
[docs] def create_token_type_ids_from_sequences(self, token_ids_0, token_ids_1=None):
"""
Creates a mask from the two sequences passed to be used in a sequence-pair classification task.
An XLM sequence pair mask has the following format:
0 0 0 0 0 0 0 0 0 0 1 1 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 (0's).
"""
sep = [self.sep_token_id]
cls = [self.cls_token_id]
if token_ids_1 is None:
return len(cls + token_ids_0 + sep) * [0]
return len(cls + token_ids_0 + sep) * [0] + len(token_ids_1 + sep) * [1]
[docs] def save_vocabulary(self, save_directory):
"""Save the tokenizer vocabulary and merge files to a directory."""
if not os.path.isdir(save_directory):
logger.error("Vocabulary path ({}) should be a directory".format(save_directory))
return
vocab_file = os.path.join(save_directory, VOCAB_FILES_NAMES['vocab_file'])
merge_file = os.path.join(save_directory, VOCAB_FILES_NAMES['merges_file'])
with open(vocab_file, 'w', encoding='utf-8') as f:
f.write(json.dumps(self.encoder, ensure_ascii=False))
index = 0
with open(merge_file, "w", encoding="utf-8") as writer:
for bpe_tokens, token_index in sorted(self.bpe_ranks.items(), key=lambda kv: kv[1]):
if index != token_index:
logger.warning("Saving vocabulary to {}: BPE merge indices are not consecutive."
" Please check that the tokenizer is not corrupted!".format(merge_file))
index = token_index
writer.write(' '.join(bpe_tokens) + u'\n')
index += 1
return vocab_file, merge_file