# coding=utf-8
# Copyright 2018 Google AI, Google Brain and Carnegie Mellon University Authors and the HuggingFace Inc. team.
# Copyright (c) 2018, NVIDIA CORPORATION. All rights reserved.
#
# 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 Transformer XL model.
Adapted from https://github.com/kimiyoung/transformer-xl.
"""
from __future__ import (absolute_import, division, print_function,
unicode_literals)
import glob
import logging
import os
import sys
from collections import Counter, OrderedDict
from io import open
import numpy as np
from .file_utils import cached_path
from .tokenization_utils import PreTrainedTokenizer
try:
import torch
except ImportError:
pass
# if sys.version_info[0] == 2:
# import cPickle as pickle
# else:
# import pickle
logger = logging.getLogger(__name__)
VOCAB_FILES_NAMES = {'pretrained_vocab_file': 'vocab.bin', 'vocab_file': 'vocab.txt'}
PRETRAINED_VOCAB_FILES_MAP = {
'pretrained_vocab_file':
{
'transfo-xl-wt103': "https://s3.amazonaws.com/models.huggingface.co/bert/transfo-xl-wt103-vocab.bin",
}
}
PRETRAINED_POSITIONAL_EMBEDDINGS_SIZES = {
'transfo-xl-wt103': None,
}
PRETRAINED_CORPUS_ARCHIVE_MAP = {
'transfo-xl-wt103': "https://s3.amazonaws.com/models.huggingface.co/bert/transfo-xl-wt103-corpus.bin",
}
CORPUS_NAME = 'corpus.bin'
[docs]class TransfoXLTokenizer(PreTrainedTokenizer):
"""
Transformer-XL tokenizer adapted from Vocab class in https://github.com/kimiyoung/transformer-xl
"""
vocab_files_names = VOCAB_FILES_NAMES
pretrained_vocab_files_map = PRETRAINED_VOCAB_FILES_MAP
max_model_input_sizes = PRETRAINED_POSITIONAL_EMBEDDINGS_SIZES
def __init__(self, special=None, min_freq=0, max_size=None, lower_case=False,
delimiter=None, vocab_file=None, pretrained_vocab_file=None,
never_split=None, unk_token="<unk>", eos_token="<eos>",
additional_special_tokens=["<formula>"], **kwargs):
super(TransfoXLTokenizer, self).__init__(unk_token=unk_token, eos_token=eos_token,
additional_special_tokens=additional_special_tokens,
**kwargs)
self.max_len_single_sentence = self.max_len # no default special tokens - you can update this value if you add special tokens
self.max_len_sentences_pair = self.max_len # no default special tokens - you can update this value if you add special tokens
if never_split is None:
never_split = self.all_special_tokens
if special is None:
special = []
self.counter = Counter()
self.special = special
self.min_freq = min_freq
self.max_size = max_size
self.lower_case = lower_case
self.delimiter = delimiter
self.vocab_file = vocab_file
self.never_split = never_split
if pretrained_vocab_file is not None:
# Hack because, honestly this tokenizer was not made to be used
# in a library like ours, at all.
vocab_dict = torch.load(pretrained_vocab_file)
for key, value in vocab_dict.items():
if key not in self.__dict__:
self.__dict__[key] = value
if vocab_file is not None:
self.build_vocab()
def count_file(self, path, verbose=False, add_eos=False):
if verbose: logger.info('counting file {} ...'.format(path))
assert os.path.exists(path)
sents = []
with open(path, 'r', encoding='utf-8') as f:
for idx, line in enumerate(f):
if verbose and idx > 0 and idx % 500000 == 0:
logger.info(' line {}'.format(idx))
symbols = self.tokenize(line, add_eos=add_eos)
self.counter.update(symbols)
sents.append(symbols)
return sents
[docs] def count_sents(self, sents, verbose=False):
"""
sents : a list of sentences, each a list of tokenized symbols
"""
if verbose: logger.info('counting {} sents ...'.format(len(sents)))
for idx, symbols in enumerate(sents):
if verbose and idx > 0 and idx % 500000 == 0:
logger.info(' line {}'.format(idx))
self.counter.update(symbols)
def _build_from_file(self, vocab_file):
self.idx2sym = []
self.sym2idx = OrderedDict()
with open(vocab_file, 'r', encoding='utf-8') as f:
for line in f:
symb = line.strip().split()[0]
self.add_symbol(symb)
if '<UNK>' in self.sym2idx:
self.unk_idx = self.sym2idx['<UNK>']
elif '<unk>' in self.sym2idx:
self.unk_idx = self.sym2idx['<unk>']
else:
raise ValueError('No <unkown> token in vocabulary')
[docs] def save_vocabulary(self, vocab_path):
"""Save the tokenizer vocabulary to a directory or file."""
if os.path.isdir(vocab_path):
vocab_file = os.path.join(vocab_path, VOCAB_FILES_NAMES['pretrained_vocab_file'])
torch.save(self.__dict__, vocab_file)
return (vocab_file,)
def build_vocab(self):
if self.vocab_file:
logger.info('building vocab from {}'.format(self.vocab_file))
self._build_from_file(self.vocab_file)
logger.info('final vocab size {}'.format(len(self)))
else:
logger.info('building vocab with min_freq={}, max_size={}'.format(
self.min_freq, self.max_size))
self.idx2sym = []
self.sym2idx = OrderedDict()
for sym in self.special:
self.add_special(sym)
for sym, cnt in self.counter.most_common(self.max_size):
if cnt < self.min_freq: break
self.add_symbol(sym)
logger.info('final vocab size {} from {} unique tokens'.format(
len(self), len(self.counter)))
def encode_file(self, path, ordered=False, verbose=False, add_eos=True,
add_double_eos=False):
if verbose: logger.info('encoding file {} ...'.format(path))
assert os.path.exists(path)
encoded = []
with open(path, 'r', encoding='utf-8') as f:
for idx, line in enumerate(f):
if verbose and idx > 0 and idx % 500000 == 0:
logger.info(' line {}'.format(idx))
symbols = self.tokenize(line, add_eos=add_eos,
add_double_eos=add_double_eos)
encoded.append(self.convert_to_tensor(symbols))
if ordered:
encoded = torch.cat(encoded)
return encoded
def encode_sents(self, sents, ordered=False, verbose=False):
if verbose: logger.info('encoding {} sents ...'.format(len(sents)))
encoded = []
for idx, symbols in enumerate(sents):
if verbose and idx > 0 and idx % 500000 == 0:
logger.info(' line {}'.format(idx))
encoded.append(self.convert_to_tensor(symbols))
if ordered:
encoded = torch.cat(encoded)
return encoded
def add_special(self, sym):
if sym not in self.sym2idx:
self.idx2sym.append(sym)
self.sym2idx[sym] = len(self.idx2sym) - 1
setattr(self, '{}_idx'.format(sym.strip('<>')), self.sym2idx[sym])
def add_symbol(self, sym):
if sym not in self.sym2idx:
self.idx2sym.append(sym)
self.sym2idx[sym] = len(self.idx2sym) - 1
def _convert_id_to_token(self, idx):
"""Converts an id in a token (BPE) using the vocab."""
assert 0 <= idx < len(self), 'Index {} out of vocabulary range'.format(idx)
return self.idx2sym[idx]
def _convert_token_to_id(self, sym):
""" Converts a token (str/unicode) in an id using the vocab. """
if sym in self.sym2idx:
return self.sym2idx[sym]
else:
# logger.info('encounter unk {}'.format(sym))
# assert '<eos>' not in sym
if hasattr(self, 'unk_idx'):
return self.sym2idx.get(sym, self.unk_idx)
# Backward compatibility with pre-trained models
elif '<unk>' in self.sym2idx:
return self.sym2idx['<unk>']
elif '<UNK>' in self.sym2idx:
return self.sym2idx['<UNK>']
else:
raise ValueError('Token not in vocabulary and no <unk> token in vocabulary for replacement')
[docs] def convert_tokens_to_string(self, tokens):
""" Converts a sequence of tokens (string) in a single string. """
out_string = ' '.join(tokens).strip()
return out_string
def convert_to_tensor(self, symbols):
return torch.LongTensor(self.convert_tokens_to_ids(symbols))
@property
def vocab_size(self):
return len(self.idx2sym)
def _tokenize(self, line, add_eos=False, add_double_eos=False):
line = line.strip()
# convert to lower case
if self.lower_case:
line = line.lower()
# empty delimiter '' will evaluate False
if self.delimiter == '':
symbols = line
else:
symbols = line.split(self.delimiter)
if add_double_eos: # lm1b
return ['<S>'] + symbols + ['<S>']
elif add_eos:
return symbols + ['<eos>']
else:
return symbols
class LMOrderedIterator(object):
def __init__(self, data, bsz, bptt, device='cpu', ext_len=None):
"""
data -- LongTensor -- the LongTensor is strictly ordered
"""
self.bsz = bsz
self.bptt = bptt
self.ext_len = ext_len if ext_len is not None else 0
self.device = device
# Work out how cleanly we can divide the dataset into bsz parts.
self.n_step = data.size(0) // bsz
# Trim off any extra elements that wouldn't cleanly fit (remainders).
data = data.narrow(0, 0, self.n_step * bsz)
# Evenly divide the data across the bsz batches.
self.data = data.view(bsz, -1).t().contiguous().to(device)
# Number of mini-batches
self.n_batch = (self.n_step + self.bptt - 1) // self.bptt
def get_batch(self, i, bptt=None):
if bptt is None: bptt = self.bptt
seq_len = min(bptt, self.data.size(0) - 1 - i)
end_idx = i + seq_len
beg_idx = max(0, i - self.ext_len)
data = self.data[beg_idx:end_idx]
target = self.data[i+1:i+1+seq_len]
data_out = data.transpose(0, 1).contiguous().to(self.device)
target_out = target.transpose(0, 1).contiguous().to(self.device)
return data_out, target_out, seq_len
def get_fixlen_iter(self, start=0):
for i in range(start, self.data.size(0) - 1, self.bptt):
yield self.get_batch(i)
def get_varlen_iter(self, start=0, std=5, min_len=5, max_deviation=3):
max_len = self.bptt + max_deviation * std
i = start
while True:
bptt = self.bptt if np.random.random() < 0.95 else self.bptt / 2.
bptt = min(max_len, max(min_len, int(np.random.normal(bptt, std))))
data, target, seq_len = self.get_batch(i, bptt)
i += seq_len
yield data, target, seq_len
if i >= self.data.size(0) - 2:
break
def __iter__(self):
return self.get_fixlen_iter()
class LMShuffledIterator(object):
def __init__(self, data, bsz, bptt, device='cpu', ext_len=None, shuffle=False):
"""
data -- list[LongTensor] -- there is no order among the LongTensors
"""
self.data = data
self.bsz = bsz
self.bptt = bptt
self.ext_len = ext_len if ext_len is not None else 0
self.device = device
self.shuffle = shuffle
def get_sent_stream(self):
# index iterator
epoch_indices = np.random.permutation(len(self.data)) if self.shuffle \
else np.array(range(len(self.data)))
# sentence iterator
for idx in epoch_indices:
yield self.data[idx]
def stream_iterator(self, sent_stream):
# streams for each data in the batch
streams = [None] * self.bsz
data = torch.LongTensor(self.bptt, self.bsz)
target = torch.LongTensor(self.bptt, self.bsz)
n_retain = 0
while True:
# data : [n_retain+bptt x bsz]
# target : [bptt x bsz]
data[n_retain:].fill_(-1)
target.fill_(-1)
valid_batch = True
for i in range(self.bsz):
n_filled = 0
try:
while n_filled < self.bptt:
if streams[i] is None or len(streams[i]) <= 1:
streams[i] = next(sent_stream)
# number of new tokens to fill in
n_new = min(len(streams[i]) - 1, self.bptt - n_filled)
# first n_retain tokens are retained from last batch
data[n_retain+n_filled:n_retain+n_filled+n_new, i] = \
streams[i][:n_new]
target[n_filled:n_filled+n_new, i] = \
streams[i][1:n_new+1]
streams[i] = streams[i][n_new:]
n_filled += n_new
except StopIteration:
valid_batch = False
break
if not valid_batch:
return
data_out = data.transpose(0, 1).contiguous().to(self.device)
target_out = target.transpose(0, 1).contiguous().to(self.device)
yield data_out, target_out, self.bptt
n_retain = min(data.size(0), self.ext_len)
if n_retain > 0:
data[:n_retain] = data[-n_retain:]
data.resize_(n_retain + self.bptt, data.size(1))
def __iter__(self):
# sent_stream is an iterator
sent_stream = self.get_sent_stream()
for batch in self.stream_iterator(sent_stream):
yield batch
class LMMultiFileIterator(LMShuffledIterator):
def __init__(self, paths, vocab, bsz, bptt, device='cpu', ext_len=None,
shuffle=False):
self.paths = paths
self.vocab = vocab
self.bsz = bsz
self.bptt = bptt
self.ext_len = ext_len if ext_len is not None else 0
self.device = device
self.shuffle = shuffle
def get_sent_stream(self, path):
sents = self.vocab.encode_file(path, add_double_eos=True)
if self.shuffle:
np.random.shuffle(sents)
sent_stream = iter(sents)
return sent_stream
def __iter__(self):
if self.shuffle:
np.random.shuffle(self.paths)
for path in self.paths:
# sent_stream is an iterator
sent_stream = self.get_sent_stream(path)
for batch in self.stream_iterator(sent_stream):
yield batch
class TransfoXLCorpus(object):
@classmethod
def from_pretrained(cls, pretrained_model_name_or_path, cache_dir=None, *inputs, **kwargs):
"""
Instantiate a pre-processed corpus.
"""
vocab = TransfoXLTokenizer.from_pretrained(pretrained_model_name_or_path, *inputs, **kwargs)
if pretrained_model_name_or_path in PRETRAINED_CORPUS_ARCHIVE_MAP:
corpus_file = PRETRAINED_CORPUS_ARCHIVE_MAP[pretrained_model_name_or_path]
else:
corpus_file = os.path.join(pretrained_model_name_or_path, CORPUS_NAME)
# redirect to the cache, if necessary
try:
resolved_corpus_file = cached_path(corpus_file, cache_dir=cache_dir)
except EnvironmentError:
logger.error(
"Corpus '{}' was not found in corpus list ({}). "
"We assumed '{}' was a path or url but couldn't find files {} "
"at this path or url.".format(
pretrained_model_name_or_path,
', '.join(PRETRAINED_CORPUS_ARCHIVE_MAP.keys()),
pretrained_model_name_or_path,
corpus_file))
return None
if resolved_corpus_file == corpus_file:
logger.info("loading corpus file {}".format(corpus_file))
else:
logger.info("loading corpus file {} from cache at {}".format(
corpus_file, resolved_corpus_file))
# Instantiate tokenizer.
corpus = cls(*inputs, **kwargs)
corpus_dict = torch.load(resolved_corpus_file)
for key, value in corpus_dict.items():
corpus.__dict__[key] = value
corpus.vocab = vocab
if corpus.train is not None:
corpus.train = torch.tensor(corpus.train, dtype=torch.long)
if corpus.valid is not None:
corpus.valid = torch.tensor(corpus.valid, dtype=torch.long)
if corpus.test is not None:
corpus.test = torch.tensor(corpus.test, dtype=torch.long)
return corpus
def __init__(self, *args, **kwargs):
self.vocab = TransfoXLTokenizer(*args, **kwargs)
self.dataset = None
self.train = None
self.valid = None
self.test = None
def build_corpus(self, path, dataset):
self.dataset = dataset
if self.dataset in ['ptb', 'wt2', 'enwik8', 'text8']:
self.vocab.count_file(os.path.join(path, 'train.txt'))
self.vocab.count_file(os.path.join(path, 'valid.txt'))
self.vocab.count_file(os.path.join(path, 'test.txt'))
elif self.dataset == 'wt103':
self.vocab.count_file(os.path.join(path, 'train.txt'))
elif self.dataset == 'lm1b':
train_path_pattern = os.path.join(
path, '1-billion-word-language-modeling-benchmark-r13output',
'training-monolingual.tokenized.shuffled', 'news.en-*')
train_paths = glob.glob(train_path_pattern)
# the vocab will load from file when build_vocab() is called
self.vocab.build_vocab()
if self.dataset in ['ptb', 'wt2', 'wt103']:
self.train = self.vocab.encode_file(
os.path.join(path, 'train.txt'), ordered=True)
self.valid = self.vocab.encode_file(
os.path.join(path, 'valid.txt'), ordered=True)
self.test = self.vocab.encode_file(
os.path.join(path, 'test.txt'), ordered=True)
elif self.dataset in ['enwik8', 'text8']:
self.train = self.vocab.encode_file(
os.path.join(path, 'train.txt'), ordered=True, add_eos=False)
self.valid = self.vocab.encode_file(
os.path.join(path, 'valid.txt'), ordered=True, add_eos=False)
self.test = self.vocab.encode_file(
os.path.join(path, 'test.txt'), ordered=True, add_eos=False)
elif self.dataset == 'lm1b':
self.train = train_paths
self.valid = self.vocab.encode_file(
os.path.join(path, 'valid.txt'), ordered=False, add_double_eos=True)
self.test = self.vocab.encode_file(
os.path.join(path, 'test.txt'), ordered=False, add_double_eos=True)
def get_iterator(self, split, *args, **kwargs):
if split == 'train':
if self.dataset in ['ptb', 'wt2', 'wt103', 'enwik8', 'text8']:
data_iter = LMOrderedIterator(self.train, *args, **kwargs)
elif self.dataset == 'lm1b':
kwargs['shuffle'] = True
data_iter = LMMultiFileIterator(self.train, self.vocab, *args, **kwargs)
elif split in ['valid', 'test']:
data = self.valid if split == 'valid' else self.test
if self.dataset in ['ptb', 'wt2', 'wt103', 'enwik8', 'text8']:
data_iter = LMOrderedIterator(data, *args, **kwargs)
elif self.dataset == 'lm1b':
data_iter = LMShuffledIterator(data, *args, **kwargs)
return data_iter
def get_lm_corpus(datadir, dataset):
fn = os.path.join(datadir, 'cache.pt')
fn_pickle = os.path.join(datadir, 'cache.pkl')
if os.path.exists(fn):
logger.info('Loading cached dataset...')
corpus = torch.load(fn_pickle)
elif os.path.exists(fn):
logger.info('Loading cached dataset from pickle...')
with open(fn, "rb") as fp:
corpus = pickle.load(fp)
else:
logger.info('Producing dataset {}...'.format(dataset))
kwargs = {}
if dataset in ['wt103', 'wt2']:
kwargs['special'] = ['<eos>']
kwargs['lower_case'] = False
elif dataset == 'ptb':
kwargs['special'] = ['<eos>']
kwargs['lower_case'] = True
elif dataset == 'lm1b':
kwargs['special'] = []
kwargs['lower_case'] = False
kwargs['vocab_file'] = os.path.join(datadir, '1b_word_vocab.txt')
elif dataset in ['enwik8', 'text8']:
pass
corpus = TransfoXLCorpus(datadir, dataset, **kwargs)
torch.save(corpus, fn)
return corpus