Documentation (#2989)

* All Tokenizers

BertTokenizer + few fixes
RobertaTokenizer
OpenAIGPTTokenizer + Fixes
GPT2Tokenizer + fixes
TransfoXLTokenizer
Correct rst for TransformerXL
XLMTokenizer + fixes
XLNet Tokenizer + Style
DistilBERT + Fix XLNet RST
CTRLTokenizer
CamemBERT Tokenizer
FlaubertTokenizer
XLMRobertaTokenizer
cleanup

* cleanup
This commit is contained in:
Lysandre Debut
2020-02-25 18:43:36 -05:00
committed by GitHub
parent c913eb9c38
commit bb7c468520
30 changed files with 866 additions and 242 deletions

View File

@@ -19,6 +19,7 @@ import collections
import logging
import os
import unicodedata
from typing import List, Optional
from tokenizers import BertWordPieceTokenizer
@@ -117,17 +118,41 @@ def whitespace_tokenize(text):
class BertTokenizer(PreTrainedTokenizer):
r"""
Constructs a BertTokenizer.
:class:`~transformers.BertTokenizer` runs end-to-end tokenization: punctuation splitting + wordpiece
Constructs a BERT tokenizer. Based on WordPiece.
This tokenizer inherits from :class:`~transformers.PreTrainedTokenizer` which contains most of the methods. Users
should refer to the superclass for more information regarding methods.
Args:
vocab_file: Path to a one-wordpiece-per-line vocabulary file
do_lower_case: Whether to lower case the input. Only has an effect when do_basic_tokenize=True
do_basic_tokenize: Whether to do basic tokenization before wordpiece.
max_len: An artificial maximum length to truncate tokenized sequences to; Effective maximum length is always the
minimum of this value (if specified) and the underlying BERT model's sequence length.
never_split: List of tokens which will never be split during tokenization. Only has an effect when
do_basic_tokenize=True
vocab_file (:obj:`string`):
File containing the vocabulary.
do_lower_case (:obj:`bool`, `optional`, defaults to :obj:`True`):
Whether to lowercase the input when tokenizing.
do_basic_tokenize (:obj:`bool`, `optional`, defaults to :obj:`True`):
Whether to do basic tokenization before WordPiece.
never_split (:obj:`bool`, `optional`, defaults to :obj:`True`):
List of tokens which will never be split during tokenization. Only has an effect when
:obj:`do_basic_tokenize=True`
unk_token (:obj:`string`, `optional`, defaults to "[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.
sep_token (:obj:`string`, `optional`, defaults to "[SEP]"):
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.
pad_token (:obj:`string`, `optional`, defaults to "[PAD]"):
The token used for padding, for example when batching sequences of different lengths.
cls_token (:obj:`string`, `optional`, defaults to "[CLS]"):
The classifier token which is used when doing sequence classification (classification of the whole
sequence instead of per-token classification). It is the first token of the sequence when built with
special tokens.
mask_token (:obj:`string`, `optional`, defaults to "[MASK]"):
The token used for masking values. This is the token used when training this model with masked language
modeling. This is the token which the model will try to predict.
tokenize_chinese_chars (:obj:`bool`, `optional`, defaults to :obj:`True`):
Whether to tokenize Chinese characters.
This should likely be deactivated for Japanese:
see: https://github.com/huggingface/transformers/issues/328
"""
vocab_files_names = VOCAB_FILES_NAMES
@@ -149,23 +174,6 @@ class BertTokenizer(PreTrainedTokenizer):
tokenize_chinese_chars=True,
**kwargs
):
"""Constructs a BertTokenizer.
Args:
**vocab_file**: Path to a one-wordpiece-per-line vocabulary file
**do_lower_case**: (`optional`) boolean (default True)
Whether to lower case the input
Only has an effect when do_basic_tokenize=True
**do_basic_tokenize**: (`optional`) boolean (default True)
Whether to do basic tokenization before wordpiece.
**never_split**: (`optional`) list of string
List of tokens which will never be split during tokenization.
Only has an effect when do_basic_tokenize=True
**tokenize_chinese_chars**: (`optional`) boolean (default True)
Whether to tokenize Chinese characters.
This should likely be deactivated for Japanese:
see: https://github.com/huggingface/pytorch-pretrained-BERT/issues/328
"""
super().__init__(
unk_token=unk_token,
sep_token=sep_token,
@@ -221,13 +229,25 @@ class BertTokenizer(PreTrainedTokenizer):
out_string = " ".join(tokens).replace(" ##", "").strip()
return out_string
def build_inputs_with_special_tokens(self, token_ids_0, token_ids_1=None):
def build_inputs_with_special_tokens(
self, token_ids_0: List[int], token_ids_1: Optional[List[int]] = None
) -> List[int]:
"""
Build model inputs from a sequence or a pair of sequence for sequence classification tasks
by concatenating and adding special tokens.
A BERT sequence has the following format:
single sequence: [CLS] X [SEP]
pair of sequences: [CLS] A [SEP] B [SEP]
- single sequence: ``[CLS] X [SEP]``
- pair of sequences: ``[CLS] A [SEP] B [SEP]``
Args:
token_ids_0 (:obj:`List[int]`):
List of IDs to which the special tokens will be added
token_ids_1 (:obj:`List[int]`, `optional`, defaults to :obj:`None`):
Optional second list of IDs for sequence pairs.
Returns:
:obj:`List[int]`: list of `input IDs <../glossary.html#input-ids>`__ with the appropriate special tokens.
"""
if token_ids_1 is None:
return [self.cls_token_id] + token_ids_0 + [self.sep_token_id]
@@ -235,20 +255,23 @@ class BertTokenizer(PreTrainedTokenizer):
sep = [self.sep_token_id]
return cls + token_ids_0 + sep + token_ids_1 + sep
def get_special_tokens_mask(self, token_ids_0, token_ids_1=None, already_has_special_tokens=False):
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]:
"""
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
token_ids_0 (:obj:`List[int]`):
List of ids.
token_ids_1 (:obj:`List[int]`, `optional`, defaults to :obj:`None`):
Optional second list of IDs for sequence pairs.
already_has_special_tokens (:obj:`bool`, `optional`, defaults to :obj:`False`):
Set to True if the token list is already formatted 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.
:obj:`List[int]`: A list of integers in the range [0, 1]: 0 for a special token, 1 for a sequence token.
"""
if already_has_special_tokens:
@@ -263,14 +286,29 @@ class BertTokenizer(PreTrainedTokenizer):
return [1] + ([0] * len(token_ids_0)) + [1] + ([0] * len(token_ids_1)) + [1]
return [1] + ([0] * len(token_ids_0)) + [1]
def create_token_type_ids_from_sequences(self, token_ids_0, token_ids_1=None):
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.
A BERT 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
::
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 (0's).
Args:
token_ids_0 (:obj:`List[int]`):
List of ids.
token_ids_1 (:obj:`List[int]`, `optional`, defaults to :obj:`None`):
Optional second list of IDs for sequence pairs.
Returns:
:obj:`List[int]`: List of `token type IDs <../glossary.html#token-type-ids>`_ according to the given
sequence(s).
"""
sep = [self.sep_token_id]
cls = [self.cls_token_id]
@@ -279,7 +317,16 @@ class BertTokenizer(PreTrainedTokenizer):
return len(cls + token_ids_0 + sep) * [0] + len(token_ids_1 + sep) * [1]
def save_vocabulary(self, vocab_path):
"""Save the tokenizer vocabulary to a directory or file."""
"""
Save the sentencepiece vocabulary (copy original file) 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.
"""
index = 0
if os.path.isdir(vocab_path):
vocab_file = os.path.join(vocab_path, VOCAB_FILES_NAMES["vocab_file"])