# 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.
"""
import glob
import logging
import os
import pickle
import re
from collections import Counter, OrderedDict
from typing import Optional
import numpy as np
from tokenizers import Tokenizer
from tokenizers.implementations import BaseTokenizer
from tokenizers.models import WordLevel
from tokenizers.normalizers import Lowercase, Sequence, Strip, unicode_normalizer_from_str
from tokenizers.pre_tokenizers import CharDelimiterSplit, WhitespaceSplit
from tokenizers.processors import BertProcessing
from .file_utils import cached_path, is_torch_available
from .tokenization_utils import PreTrainedTokenizer, PreTrainedTokenizerFast
if is_torch_available():
import torch
logger = logging.getLogger(__name__)
VOCAB_FILES_NAMES = {"pretrained_vocab_file": "vocab.bin", "vocab_file": "vocab.txt"}
VOCAB_FILES_NAMES_FAST = {"pretrained_vocab_file": "vocab.json", "vocab_file": "vocab.json"}
PRETRAINED_VOCAB_FILES_MAP = {
"pretrained_vocab_file": {
"transfo-xl-wt103": "https://s3.amazonaws.com/models.huggingface.co/bert/transfo-xl-wt103-vocab.bin",
}
}
PRETRAINED_VOCAB_FILES_MAP_FAST = {
"pretrained_vocab_file": {
"transfo-xl-wt103": "https://s3.amazonaws.com/models.huggingface.co/bert/transfo-xl-wt103-vocab.json",
}
}
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
This tokenizer inherits from :class:`~transformers.PreTrainedTokenizer` which contains most of the methods. Users
should refer to the superclass for more information regarding methods.
"""
vocab_files_names = VOCAB_FILES_NAMES
pretrained_vocab_files_map = PRETRAINED_VOCAB_FILES_MAP
max_model_input_sizes = PRETRAINED_POSITIONAL_EMBEDDINGS_SIZES
model_input_names = []
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().__init__(
unk_token=unk_token, eos_token=eos_token, additional_special_tokens=additional_special_tokens, **kwargs
)
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
self.punctuation_symbols = '!"#$%&()*+,-./\:;<=>?@[\\]^_`{|}~' # noqa: W605
self.punction_without_space_before_pattern = re.compile(r"[^\s][{}]".format(self.punctuation_symbols))
self.punctuation_with_space_around_pattern = self._compile_space_around_punctuation_pattern()
try:
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()
except Exception:
raise ValueError(
"Unable to parse file {}. Unknown format. "
"If you tried to load a model saved through TransfoXLTokenizerFast,"
"please note they are not compatible.".format(pretrained_vocab_file)
)
if vocab_file is not None:
self.build_vocab()
def _compile_space_around_punctuation_pattern(self):
look_ahead_for_special_token = "(?=[{}])".format(self.punctuation_symbols)
look_ahead_to_match_all_except_space = "(?=[^\s])" # noqa: W605
return re.compile(r"" + look_ahead_for_special_token + look_ahead_to_match_all_except_space)
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
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 vocabulary and special tokens file to a directory.
Args:
vocab_path (:obj:`str`):
The directory in which to save the vocabulary.
Returns:
:obj:`Tuple(str)`: Paths to the files saved.
"""
logger.warning(
"Please note you will not be able to load the save vocabulary in"
" Rust-based TransfoXLTokenizerFast as they don't share the same structure."
)
if os.path.isdir(vocab_path):
vocab_file = os.path.join(vocab_path, VOCAB_FILES_NAMES["pretrained_vocab_file"])
else:
vocab_file = vocab_path
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) 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")
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 get_vocab(self):
return dict(self.sym2idx, **self.added_tokens_encoder)
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
def prepare_for_tokenization(self, text, **kwargs):
# add spaces before punctuation symbols as should be done in transfo-xl
if "add_space_before_punct_symbol" in kwargs and kwargs["add_space_before_punct_symbol"]:
text = self.punctuation_with_space_around_pattern.sub(r" ", text)
elif self.punction_without_space_before_pattern.search(text):
# searches until the first occurence of a punctuation symbol without surrounding spaces
logger.warning(
"You might want to consider setting `add_space_before_punct_symbol=True` as an argument to the `tokenizer.encode()` to avoid tokenizing words with punctuation symbols to the `<unk>` token"
)
return text
class _TransfoXLDelimiterLookupTokenizer(BaseTokenizer):
def __init__(
self,
vocab_file,
delimiter,
lowercase,
unk_token,
eos_token,
add_eos=False,
add_double_eos=False,
normalization: Optional[str] = None,
):
try:
tokenizer = WordLevel(vocab_file, unk_token=unk_token)
tokenizer = Tokenizer(tokenizer)
except Exception:
raise ValueError(
"Unable to parse file {}. Unknown format. "
"If you tried to load a model saved through TransfoXLTokenizer,"
"please note they are not compatible.".format(vocab_file)
)
# Create the correct normalization path
normalizer = []
# Include unicode normalization
if normalization:
normalizer += [unicode_normalizer_from_str(normalization)]
# Include case normalization
if lowercase:
normalizer += [Lowercase()]
# Strip normalizer at the end
normalizer += [Strip(left=True, right=True)]
if len(normalizer) > 0:
tokenizer.normalizer = Sequence(normalizer) if len(normalizer) > 1 else normalizer[0]
# Setup the splitter
tokenizer.pre_tokenizer = CharDelimiterSplit(delimiter) if delimiter else WhitespaceSplit()
if add_double_eos:
tokenizer.post_processor = BertProcessing(
(eos_token, tokenizer.token_to_id(eos_token)), (eos_token, tokenizer.token_to_id(eos_token))
)
parameters = {
"model": "TransfoXLModel",
"add_eos": add_eos,
"add_double_eos": add_double_eos,
"unk_token": unk_token,
"eos_token": eos_token,
"delimiter": delimiter,
"lowercase": lowercase,
}
super().__init__(tokenizer, parameters)
[docs]class TransfoXLTokenizerFast(PreTrainedTokenizerFast):
"""
Construct a "Fast" Transformer-XL tokenizer (backed by HuggingFace's `tokenizers` library).
The Transformer-XL tokenizer is a word-level tokenizer (no sub-word tokenization).
Adapted from Vocab class in https://github.com/kimiyoung/transformer-xl
This tokenizer inherits from :class:`~transformers.PreTrainedTokenizerFast` which contains most of the methods. Users
should refer to the superclass for more information regarding methods.
"""
vocab_files_names = VOCAB_FILES_NAMES_FAST
pretrained_vocab_files_map = PRETRAINED_VOCAB_FILES_MAP_FAST
max_model_input_sizes = PRETRAINED_POSITIONAL_EMBEDDINGS_SIZES
model_input_names = []
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>"],
add_eos=False,
add_double_eos=False,
normalization=None,
**kwargs
):
super().__init__(
_TransfoXLDelimiterLookupTokenizer(
vocab_file=vocab_file or pretrained_vocab_file,
delimiter=delimiter,
lowercase=lower_case,
unk_token=unk_token,
eos_token=eos_token,
add_eos=add_eos,
add_double_eos=add_double_eos,
normalization=normalization,
),
unk_token=unk_token,
eos_token=eos_token,
additional_special_tokens=additional_special_tokens,
**kwargs,
)
[docs] def save_pretrained(self, save_directory):
logger.warning(
"Please note you will not be able to load the vocabulary in"
" Python-based TransfoXLTokenizer as they don't share the same structure."
)
return super().save_pretrained(save_directory)
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 / 2.0
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