846 lines
32 KiB
Python
846 lines
32 KiB
Python
# Copyright 2020 The HuggingFace Team. All rights reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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import json
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import os
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from functools import partial
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from multiprocessing import Pool, cpu_count
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import numpy as np
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from tqdm import tqdm
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from ...models.bert.tokenization_bert import whitespace_tokenize
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from ...tokenization_utils_base import BatchEncoding, PreTrainedTokenizerBase, TruncationStrategy
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from ...utils import is_tf_available, is_torch_available, logging
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from .utils import DataProcessor
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# Store the tokenizers which insert 2 separators tokens
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MULTI_SEP_TOKENS_TOKENIZERS_SET = {"roberta", "camembert", "bart", "mpnet"}
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if is_torch_available():
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import torch
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from torch.utils.data import TensorDataset
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if is_tf_available():
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import tensorflow as tf
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logger = logging.get_logger(__name__)
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def _improve_answer_span(doc_tokens, input_start, input_end, tokenizer, orig_answer_text):
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"""Returns tokenized answer spans that better match the annotated answer."""
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tok_answer_text = " ".join(tokenizer.tokenize(orig_answer_text))
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for new_start in range(input_start, input_end + 1):
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for new_end in range(input_end, new_start - 1, -1):
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text_span = " ".join(doc_tokens[new_start : (new_end + 1)])
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if text_span == tok_answer_text:
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return (new_start, new_end)
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return (input_start, input_end)
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def _check_is_max_context(doc_spans, cur_span_index, position):
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"""Check if this is the 'max context' doc span for the token."""
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best_score = None
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best_span_index = None
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for span_index, doc_span in enumerate(doc_spans):
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end = doc_span.start + doc_span.length - 1
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if position < doc_span.start:
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continue
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if position > end:
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continue
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num_left_context = position - doc_span.start
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num_right_context = end - position
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score = min(num_left_context, num_right_context) + 0.01 * doc_span.length
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if best_score is None or score > best_score:
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best_score = score
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best_span_index = span_index
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return cur_span_index == best_span_index
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def _new_check_is_max_context(doc_spans, cur_span_index, position):
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"""Check if this is the 'max context' doc span for the token."""
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# if len(doc_spans) == 1:
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# return True
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best_score = None
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best_span_index = None
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for span_index, doc_span in enumerate(doc_spans):
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end = doc_span["start"] + doc_span["length"] - 1
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if position < doc_span["start"]:
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continue
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if position > end:
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continue
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num_left_context = position - doc_span["start"]
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num_right_context = end - position
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score = min(num_left_context, num_right_context) + 0.01 * doc_span["length"]
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if best_score is None or score > best_score:
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best_score = score
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best_span_index = span_index
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return cur_span_index == best_span_index
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def _is_whitespace(c):
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if c == " " or c == "\t" or c == "\r" or c == "\n" or ord(c) == 0x202F:
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return True
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return False
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def squad_convert_example_to_features(
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example, max_seq_length, doc_stride, max_query_length, padding_strategy, is_training
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):
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features = []
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if is_training and not example.is_impossible:
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# Get start and end position
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start_position = example.start_position
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end_position = example.end_position
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# If the answer cannot be found in the text, then skip this example.
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actual_text = " ".join(example.doc_tokens[start_position : (end_position + 1)])
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cleaned_answer_text = " ".join(whitespace_tokenize(example.answer_text))
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if actual_text.find(cleaned_answer_text) == -1:
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logger.warning(f"Could not find answer: '{actual_text}' vs. '{cleaned_answer_text}'")
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return []
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tok_to_orig_index = []
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orig_to_tok_index = []
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all_doc_tokens = []
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for i, token in enumerate(example.doc_tokens):
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orig_to_tok_index.append(len(all_doc_tokens))
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if tokenizer.__class__.__name__ in [
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"RobertaTokenizer",
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"LongformerTokenizer",
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"BartTokenizer",
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"RobertaTokenizerFast",
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"LongformerTokenizerFast",
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"BartTokenizerFast",
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]:
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sub_tokens = tokenizer.tokenize(token, add_prefix_space=True)
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else:
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sub_tokens = tokenizer.tokenize(token)
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for sub_token in sub_tokens:
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tok_to_orig_index.append(i)
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all_doc_tokens.append(sub_token)
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if is_training and not example.is_impossible:
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tok_start_position = orig_to_tok_index[example.start_position]
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if example.end_position < len(example.doc_tokens) - 1:
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tok_end_position = orig_to_tok_index[example.end_position + 1] - 1
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else:
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tok_end_position = len(all_doc_tokens) - 1
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(tok_start_position, tok_end_position) = _improve_answer_span(
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all_doc_tokens, tok_start_position, tok_end_position, tokenizer, example.answer_text
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)
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spans = []
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truncated_query = tokenizer.encode(
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example.question_text, add_special_tokens=False, truncation=True, max_length=max_query_length
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)
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# Tokenizers who insert 2 SEP tokens in-between <context> & <question> need to have special handling
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# in the way they compute mask of added tokens.
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tokenizer_type = type(tokenizer).__name__.replace("Tokenizer", "").lower()
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sequence_added_tokens = (
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tokenizer.model_max_length - tokenizer.max_len_single_sentence + 1
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if tokenizer_type in MULTI_SEP_TOKENS_TOKENIZERS_SET
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else tokenizer.model_max_length - tokenizer.max_len_single_sentence
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)
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sequence_pair_added_tokens = tokenizer.model_max_length - tokenizer.max_len_sentences_pair
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span_doc_tokens = all_doc_tokens
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while len(spans) * doc_stride < len(all_doc_tokens):
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# Define the side we want to truncate / pad and the text/pair sorting
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if tokenizer.padding_side == "right":
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texts = truncated_query
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pairs = span_doc_tokens
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truncation = TruncationStrategy.ONLY_SECOND.value
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else:
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texts = span_doc_tokens
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pairs = truncated_query
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truncation = TruncationStrategy.ONLY_FIRST.value
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encoded_dict = tokenizer.encode_plus( # TODO(thom) update this logic
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texts,
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pairs,
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truncation=truncation,
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padding=padding_strategy,
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max_length=max_seq_length,
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return_overflowing_tokens=True,
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stride=max_seq_length - doc_stride - len(truncated_query) - sequence_pair_added_tokens,
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return_token_type_ids=True,
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)
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paragraph_len = min(
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len(all_doc_tokens) - len(spans) * doc_stride,
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max_seq_length - len(truncated_query) - sequence_pair_added_tokens,
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)
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if tokenizer.pad_token_id in encoded_dict["input_ids"]:
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if tokenizer.padding_side == "right":
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non_padded_ids = encoded_dict["input_ids"][: encoded_dict["input_ids"].index(tokenizer.pad_token_id)]
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else:
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last_padding_id_position = (
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len(encoded_dict["input_ids"]) - 1 - encoded_dict["input_ids"][::-1].index(tokenizer.pad_token_id)
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)
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non_padded_ids = encoded_dict["input_ids"][last_padding_id_position + 1 :]
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else:
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non_padded_ids = encoded_dict["input_ids"]
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tokens = tokenizer.convert_ids_to_tokens(non_padded_ids)
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token_to_orig_map = {}
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for i in range(paragraph_len):
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index = len(truncated_query) + sequence_added_tokens + i if tokenizer.padding_side == "right" else i
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token_to_orig_map[index] = tok_to_orig_index[len(spans) * doc_stride + i]
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encoded_dict["paragraph_len"] = paragraph_len
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encoded_dict["tokens"] = tokens
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encoded_dict["token_to_orig_map"] = token_to_orig_map
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encoded_dict["truncated_query_with_special_tokens_length"] = len(truncated_query) + sequence_added_tokens
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encoded_dict["token_is_max_context"] = {}
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encoded_dict["start"] = len(spans) * doc_stride
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encoded_dict["length"] = paragraph_len
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spans.append(encoded_dict)
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if "overflowing_tokens" not in encoded_dict or (
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"overflowing_tokens" in encoded_dict and len(encoded_dict["overflowing_tokens"]) == 0
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):
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break
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span_doc_tokens = encoded_dict["overflowing_tokens"]
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for doc_span_index in range(len(spans)):
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for j in range(spans[doc_span_index]["paragraph_len"]):
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is_max_context = _new_check_is_max_context(spans, doc_span_index, doc_span_index * doc_stride + j)
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index = (
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j
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if tokenizer.padding_side == "left"
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else spans[doc_span_index]["truncated_query_with_special_tokens_length"] + j
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)
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spans[doc_span_index]["token_is_max_context"][index] = is_max_context
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for span in spans:
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# Identify the position of the CLS token
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cls_index = span["input_ids"].index(tokenizer.cls_token_id)
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# p_mask: mask with 1 for token than cannot be in the answer (0 for token which can be in an answer)
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# Original TF implementation also keep the classification token (set to 0)
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p_mask = np.ones_like(span["token_type_ids"])
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if tokenizer.padding_side == "right":
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p_mask[len(truncated_query) + sequence_added_tokens :] = 0
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else:
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p_mask[-len(span["tokens"]) : -(len(truncated_query) + sequence_added_tokens)] = 0
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pad_token_indices = np.where(span["input_ids"] == tokenizer.pad_token_id)
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special_token_indices = np.asarray(
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tokenizer.get_special_tokens_mask(span["input_ids"], already_has_special_tokens=True)
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).nonzero()
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p_mask[pad_token_indices] = 1
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p_mask[special_token_indices] = 1
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# Set the cls index to 0: the CLS index can be used for impossible answers
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p_mask[cls_index] = 0
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span_is_impossible = example.is_impossible
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start_position = 0
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end_position = 0
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if is_training and not span_is_impossible:
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# For training, if our document chunk does not contain an annotation
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# we throw it out, since there is nothing to predict.
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doc_start = span["start"]
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doc_end = span["start"] + span["length"] - 1
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out_of_span = False
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if not (tok_start_position >= doc_start and tok_end_position <= doc_end):
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out_of_span = True
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if out_of_span:
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start_position = cls_index
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end_position = cls_index
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span_is_impossible = True
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else:
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if tokenizer.padding_side == "left":
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doc_offset = 0
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else:
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doc_offset = len(truncated_query) + sequence_added_tokens
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start_position = tok_start_position - doc_start + doc_offset
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end_position = tok_end_position - doc_start + doc_offset
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features.append(
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SquadFeatures(
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span["input_ids"],
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span["attention_mask"],
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span["token_type_ids"],
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cls_index,
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p_mask.tolist(),
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example_index=0, # Can not set unique_id and example_index here. They will be set after multiple processing.
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unique_id=0,
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paragraph_len=span["paragraph_len"],
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token_is_max_context=span["token_is_max_context"],
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tokens=span["tokens"],
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token_to_orig_map=span["token_to_orig_map"],
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start_position=start_position,
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end_position=end_position,
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is_impossible=span_is_impossible,
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qas_id=example.qas_id,
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)
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)
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return features
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def squad_convert_example_to_features_init(tokenizer_for_convert: PreTrainedTokenizerBase):
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global tokenizer
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tokenizer = tokenizer_for_convert
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def squad_convert_examples_to_features(
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examples,
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tokenizer,
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max_seq_length,
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doc_stride,
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max_query_length,
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is_training,
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padding_strategy="max_length",
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return_dataset=False,
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threads=1,
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tqdm_enabled=True,
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):
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"""
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Converts a list of examples into a list of features that can be directly given as input to a model. It is
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model-dependant and takes advantage of many of the tokenizer's features to create the model's inputs.
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Args:
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examples: list of [`~data.processors.squad.SquadExample`]
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tokenizer: an instance of a child of [`PreTrainedTokenizer`]
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max_seq_length: The maximum sequence length of the inputs.
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doc_stride: The stride used when the context is too large and is split across several features.
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max_query_length: The maximum length of the query.
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is_training: whether to create features for model evaluation or model training.
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padding_strategy: Default to "max_length". Which padding strategy to use
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return_dataset: Default False. Either 'pt' or 'tf'.
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if 'pt': returns a torch.data.TensorDataset, if 'tf': returns a tf.data.Dataset
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threads: multiple processing threads.
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Returns:
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list of [`~data.processors.squad.SquadFeatures`]
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Example:
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```python
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processor = SquadV2Processor()
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examples = processor.get_dev_examples(data_dir)
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features = squad_convert_examples_to_features(
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examples=examples,
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tokenizer=tokenizer,
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max_seq_length=args.max_seq_length,
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doc_stride=args.doc_stride,
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max_query_length=args.max_query_length,
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is_training=not evaluate,
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)
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```"""
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# Defining helper methods
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features = []
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threads = min(threads, cpu_count())
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with Pool(threads, initializer=squad_convert_example_to_features_init, initargs=(tokenizer,)) as p:
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annotate_ = partial(
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squad_convert_example_to_features,
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max_seq_length=max_seq_length,
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doc_stride=doc_stride,
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max_query_length=max_query_length,
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padding_strategy=padding_strategy,
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is_training=is_training,
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)
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features = list(
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tqdm(
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p.imap(annotate_, examples, chunksize=32),
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total=len(examples),
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desc="convert squad examples to features",
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disable=not tqdm_enabled,
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)
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)
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new_features = []
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unique_id = 1000000000
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example_index = 0
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for example_features in tqdm(
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features, total=len(features), desc="add example index and unique id", disable=not tqdm_enabled
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):
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if not example_features:
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continue
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for example_feature in example_features:
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example_feature.example_index = example_index
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example_feature.unique_id = unique_id
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new_features.append(example_feature)
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unique_id += 1
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example_index += 1
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features = new_features
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del new_features
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if return_dataset == "pt":
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if not is_torch_available():
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raise RuntimeError("PyTorch must be installed to return a PyTorch dataset.")
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# Convert to Tensors and build dataset
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all_input_ids = torch.tensor([f.input_ids for f in features], dtype=torch.long)
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all_attention_masks = torch.tensor([f.attention_mask for f in features], dtype=torch.long)
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all_token_type_ids = torch.tensor([f.token_type_ids for f in features], dtype=torch.long)
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all_cls_index = torch.tensor([f.cls_index for f in features], dtype=torch.long)
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all_p_mask = torch.tensor([f.p_mask for f in features], dtype=torch.float)
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all_is_impossible = torch.tensor([f.is_impossible for f in features], dtype=torch.float)
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if not is_training:
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all_feature_index = torch.arange(all_input_ids.size(0), dtype=torch.long)
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dataset = TensorDataset(
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all_input_ids, all_attention_masks, all_token_type_ids, all_feature_index, all_cls_index, all_p_mask
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)
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else:
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all_start_positions = torch.tensor([f.start_position for f in features], dtype=torch.long)
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all_end_positions = torch.tensor([f.end_position for f in features], dtype=torch.long)
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dataset = TensorDataset(
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all_input_ids,
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all_attention_masks,
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all_token_type_ids,
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all_start_positions,
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all_end_positions,
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all_cls_index,
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all_p_mask,
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all_is_impossible,
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)
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return features, dataset
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elif return_dataset == "tf":
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if not is_tf_available():
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raise RuntimeError("TensorFlow must be installed to return a TensorFlow dataset.")
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def gen():
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for i, ex in enumerate(features):
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if ex.token_type_ids is None:
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yield (
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{
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"input_ids": ex.input_ids,
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"attention_mask": ex.attention_mask,
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"feature_index": i,
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"qas_id": ex.qas_id,
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},
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{
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"start_positions": ex.start_position,
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"end_positions": ex.end_position,
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"cls_index": ex.cls_index,
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"p_mask": ex.p_mask,
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"is_impossible": ex.is_impossible,
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},
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)
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else:
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yield (
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{
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"input_ids": ex.input_ids,
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"attention_mask": ex.attention_mask,
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"token_type_ids": ex.token_type_ids,
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"feature_index": i,
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"qas_id": ex.qas_id,
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},
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{
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"start_positions": ex.start_position,
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"end_positions": ex.end_position,
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"cls_index": ex.cls_index,
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"p_mask": ex.p_mask,
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"is_impossible": ex.is_impossible,
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},
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)
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# Why have we split the batch into a tuple? PyTorch just has a list of tensors.
|
|
if "token_type_ids" in tokenizer.model_input_names:
|
|
train_types = (
|
|
{
|
|
"input_ids": tf.int32,
|
|
"attention_mask": tf.int32,
|
|
"token_type_ids": tf.int32,
|
|
"feature_index": tf.int64,
|
|
"qas_id": tf.string,
|
|
},
|
|
{
|
|
"start_positions": tf.int64,
|
|
"end_positions": tf.int64,
|
|
"cls_index": tf.int64,
|
|
"p_mask": tf.int32,
|
|
"is_impossible": tf.int32,
|
|
},
|
|
)
|
|
|
|
train_shapes = (
|
|
{
|
|
"input_ids": tf.TensorShape([None]),
|
|
"attention_mask": tf.TensorShape([None]),
|
|
"token_type_ids": tf.TensorShape([None]),
|
|
"feature_index": tf.TensorShape([]),
|
|
"qas_id": tf.TensorShape([]),
|
|
},
|
|
{
|
|
"start_positions": tf.TensorShape([]),
|
|
"end_positions": tf.TensorShape([]),
|
|
"cls_index": tf.TensorShape([]),
|
|
"p_mask": tf.TensorShape([None]),
|
|
"is_impossible": tf.TensorShape([]),
|
|
},
|
|
)
|
|
else:
|
|
train_types = (
|
|
{"input_ids": tf.int32, "attention_mask": tf.int32, "feature_index": tf.int64, "qas_id": tf.string},
|
|
{
|
|
"start_positions": tf.int64,
|
|
"end_positions": tf.int64,
|
|
"cls_index": tf.int64,
|
|
"p_mask": tf.int32,
|
|
"is_impossible": tf.int32,
|
|
},
|
|
)
|
|
|
|
train_shapes = (
|
|
{
|
|
"input_ids": tf.TensorShape([None]),
|
|
"attention_mask": tf.TensorShape([None]),
|
|
"feature_index": tf.TensorShape([]),
|
|
"qas_id": tf.TensorShape([]),
|
|
},
|
|
{
|
|
"start_positions": tf.TensorShape([]),
|
|
"end_positions": tf.TensorShape([]),
|
|
"cls_index": tf.TensorShape([]),
|
|
"p_mask": tf.TensorShape([None]),
|
|
"is_impossible": tf.TensorShape([]),
|
|
},
|
|
)
|
|
|
|
return tf.data.Dataset.from_generator(gen, train_types, train_shapes)
|
|
else:
|
|
return features
|
|
|
|
|
|
class SquadProcessor(DataProcessor):
|
|
"""
|
|
Processor for the SQuAD data set. overridden by SquadV1Processor and SquadV2Processor, used by the version 1.1 and
|
|
version 2.0 of SQuAD, respectively.
|
|
"""
|
|
|
|
train_file = None
|
|
dev_file = None
|
|
|
|
def _get_example_from_tensor_dict(self, tensor_dict, evaluate=False):
|
|
if not evaluate:
|
|
answer = tensor_dict["answers"]["text"][0].numpy().decode("utf-8")
|
|
answer_start = tensor_dict["answers"]["answer_start"][0].numpy()
|
|
answers = []
|
|
else:
|
|
answers = [
|
|
{"answer_start": start.numpy(), "text": text.numpy().decode("utf-8")}
|
|
for start, text in zip(tensor_dict["answers"]["answer_start"], tensor_dict["answers"]["text"])
|
|
]
|
|
|
|
answer = None
|
|
answer_start = None
|
|
|
|
return SquadExample(
|
|
qas_id=tensor_dict["id"].numpy().decode("utf-8"),
|
|
question_text=tensor_dict["question"].numpy().decode("utf-8"),
|
|
context_text=tensor_dict["context"].numpy().decode("utf-8"),
|
|
answer_text=answer,
|
|
start_position_character=answer_start,
|
|
title=tensor_dict["title"].numpy().decode("utf-8"),
|
|
answers=answers,
|
|
)
|
|
|
|
def get_examples_from_dataset(self, dataset, evaluate=False):
|
|
"""
|
|
Creates a list of [`~data.processors.squad.SquadExample`] using a TFDS dataset.
|
|
|
|
Args:
|
|
dataset: The tfds dataset loaded from *tensorflow_datasets.load("squad")*
|
|
evaluate: Boolean specifying if in evaluation mode or in training mode
|
|
|
|
Returns:
|
|
List of SquadExample
|
|
|
|
Examples:
|
|
|
|
```python
|
|
>>> import tensorflow_datasets as tfds
|
|
|
|
>>> dataset = tfds.load("squad")
|
|
|
|
>>> training_examples = get_examples_from_dataset(dataset, evaluate=False)
|
|
>>> evaluation_examples = get_examples_from_dataset(dataset, evaluate=True)
|
|
```"""
|
|
|
|
if evaluate:
|
|
dataset = dataset["validation"]
|
|
else:
|
|
dataset = dataset["train"]
|
|
|
|
examples = []
|
|
for tensor_dict in tqdm(dataset):
|
|
examples.append(self._get_example_from_tensor_dict(tensor_dict, evaluate=evaluate))
|
|
|
|
return examples
|
|
|
|
def get_train_examples(self, data_dir, filename=None):
|
|
"""
|
|
Returns the training examples from the data directory.
|
|
|
|
Args:
|
|
data_dir: Directory containing the data files used for training and evaluating.
|
|
filename: None by default, specify this if the training file has a different name than the original one
|
|
which is `train-v1.1.json` and `train-v2.0.json` for squad versions 1.1 and 2.0 respectively.
|
|
|
|
"""
|
|
if data_dir is None:
|
|
data_dir = ""
|
|
|
|
if self.train_file is None:
|
|
raise ValueError("SquadProcessor should be instantiated via SquadV1Processor or SquadV2Processor")
|
|
|
|
with open(
|
|
os.path.join(data_dir, self.train_file if filename is None else filename), "r", encoding="utf-8"
|
|
) as reader:
|
|
input_data = json.load(reader)["data"]
|
|
return self._create_examples(input_data, "train")
|
|
|
|
def get_dev_examples(self, data_dir, filename=None):
|
|
"""
|
|
Returns the evaluation example from the data directory.
|
|
|
|
Args:
|
|
data_dir: Directory containing the data files used for training and evaluating.
|
|
filename: None by default, specify this if the evaluation file has a different name than the original one
|
|
which is `dev-v1.1.json` and `dev-v2.0.json` for squad versions 1.1 and 2.0 respectively.
|
|
"""
|
|
if data_dir is None:
|
|
data_dir = ""
|
|
|
|
if self.dev_file is None:
|
|
raise ValueError("SquadProcessor should be instantiated via SquadV1Processor or SquadV2Processor")
|
|
|
|
with open(
|
|
os.path.join(data_dir, self.dev_file if filename is None else filename), "r", encoding="utf-8"
|
|
) as reader:
|
|
input_data = json.load(reader)["data"]
|
|
return self._create_examples(input_data, "dev")
|
|
|
|
def _create_examples(self, input_data, set_type):
|
|
is_training = set_type == "train"
|
|
examples = []
|
|
for entry in tqdm(input_data):
|
|
title = entry["title"]
|
|
for paragraph in entry["paragraphs"]:
|
|
context_text = paragraph["context"]
|
|
for qa in paragraph["qas"]:
|
|
qas_id = qa["id"]
|
|
question_text = qa["question"]
|
|
start_position_character = None
|
|
answer_text = None
|
|
answers = []
|
|
|
|
is_impossible = qa.get("is_impossible", False)
|
|
if not is_impossible:
|
|
if is_training:
|
|
answer = qa["answers"][0]
|
|
answer_text = answer["text"]
|
|
start_position_character = answer["answer_start"]
|
|
else:
|
|
answers = qa["answers"]
|
|
|
|
example = SquadExample(
|
|
qas_id=qas_id,
|
|
question_text=question_text,
|
|
context_text=context_text,
|
|
answer_text=answer_text,
|
|
start_position_character=start_position_character,
|
|
title=title,
|
|
is_impossible=is_impossible,
|
|
answers=answers,
|
|
)
|
|
examples.append(example)
|
|
return examples
|
|
|
|
|
|
class SquadV1Processor(SquadProcessor):
|
|
train_file = "train-v1.1.json"
|
|
dev_file = "dev-v1.1.json"
|
|
|
|
|
|
class SquadV2Processor(SquadProcessor):
|
|
train_file = "train-v2.0.json"
|
|
dev_file = "dev-v2.0.json"
|
|
|
|
|
|
class SquadExample:
|
|
"""
|
|
A single training/test example for the Squad dataset, as loaded from disk.
|
|
|
|
Args:
|
|
qas_id: The example's unique identifier
|
|
question_text: The question string
|
|
context_text: The context string
|
|
answer_text: The answer string
|
|
start_position_character: The character position of the start of the answer
|
|
title: The title of the example
|
|
answers: None by default, this is used during evaluation. Holds answers as well as their start positions.
|
|
is_impossible: False by default, set to True if the example has no possible answer.
|
|
"""
|
|
|
|
def __init__(
|
|
self,
|
|
qas_id,
|
|
question_text,
|
|
context_text,
|
|
answer_text,
|
|
start_position_character,
|
|
title,
|
|
answers=[],
|
|
is_impossible=False,
|
|
):
|
|
self.qas_id = qas_id
|
|
self.question_text = question_text
|
|
self.context_text = context_text
|
|
self.answer_text = answer_text
|
|
self.title = title
|
|
self.is_impossible = is_impossible
|
|
self.answers = answers
|
|
|
|
self.start_position, self.end_position = 0, 0
|
|
|
|
doc_tokens = []
|
|
char_to_word_offset = []
|
|
prev_is_whitespace = True
|
|
|
|
# Split on whitespace so that different tokens may be attributed to their original position.
|
|
for c in self.context_text:
|
|
if _is_whitespace(c):
|
|
prev_is_whitespace = True
|
|
else:
|
|
if prev_is_whitespace:
|
|
doc_tokens.append(c)
|
|
else:
|
|
doc_tokens[-1] += c
|
|
prev_is_whitespace = False
|
|
char_to_word_offset.append(len(doc_tokens) - 1)
|
|
|
|
self.doc_tokens = doc_tokens
|
|
self.char_to_word_offset = char_to_word_offset
|
|
|
|
# Start and end positions only has a value during evaluation.
|
|
if start_position_character is not None and not is_impossible:
|
|
self.start_position = char_to_word_offset[start_position_character]
|
|
self.end_position = char_to_word_offset[
|
|
min(start_position_character + len(answer_text) - 1, len(char_to_word_offset) - 1)
|
|
]
|
|
|
|
|
|
class SquadFeatures:
|
|
"""
|
|
Single squad example features to be fed to a model. Those features are model-specific and can be crafted from
|
|
[`~data.processors.squad.SquadExample`] using the
|
|
:method:*~transformers.data.processors.squad.squad_convert_examples_to_features* method.
|
|
|
|
Args:
|
|
input_ids: Indices of input sequence tokens in the vocabulary.
|
|
attention_mask: Mask to avoid performing attention on padding token indices.
|
|
token_type_ids: Segment token indices to indicate first and second portions of the inputs.
|
|
cls_index: the index of the CLS token.
|
|
p_mask: Mask identifying tokens that can be answers vs. tokens that cannot.
|
|
Mask with 1 for tokens than cannot be in the answer and 0 for token that can be in an answer
|
|
example_index: the index of the example
|
|
unique_id: The unique Feature identifier
|
|
paragraph_len: The length of the context
|
|
token_is_max_context:
|
|
List of booleans identifying which tokens have their maximum context in this feature object. If a token
|
|
does not have their maximum context in this feature object, it means that another feature object has more
|
|
information related to that token and should be prioritized over this feature for that token.
|
|
tokens: list of tokens corresponding to the input ids
|
|
token_to_orig_map: mapping between the tokens and the original text, needed in order to identify the answer.
|
|
start_position: start of the answer token index
|
|
end_position: end of the answer token index
|
|
encoding: optionally store the BatchEncoding with the fast-tokenizer alignment methods.
|
|
"""
|
|
|
|
def __init__(
|
|
self,
|
|
input_ids,
|
|
attention_mask,
|
|
token_type_ids,
|
|
cls_index,
|
|
p_mask,
|
|
example_index,
|
|
unique_id,
|
|
paragraph_len,
|
|
token_is_max_context,
|
|
tokens,
|
|
token_to_orig_map,
|
|
start_position,
|
|
end_position,
|
|
is_impossible,
|
|
qas_id: str = None,
|
|
encoding: BatchEncoding = None,
|
|
):
|
|
self.input_ids = input_ids
|
|
self.attention_mask = attention_mask
|
|
self.token_type_ids = token_type_ids
|
|
self.cls_index = cls_index
|
|
self.p_mask = p_mask
|
|
|
|
self.example_index = example_index
|
|
self.unique_id = unique_id
|
|
self.paragraph_len = paragraph_len
|
|
self.token_is_max_context = token_is_max_context
|
|
self.tokens = tokens
|
|
self.token_to_orig_map = token_to_orig_map
|
|
|
|
self.start_position = start_position
|
|
self.end_position = end_position
|
|
self.is_impossible = is_impossible
|
|
self.qas_id = qas_id
|
|
|
|
self.encoding = encoding
|
|
|
|
|
|
class SquadResult:
|
|
"""
|
|
Constructs a SquadResult which can be used to evaluate a model's output on the SQuAD dataset.
|
|
|
|
Args:
|
|
unique_id: The unique identifier corresponding to that example.
|
|
start_logits: The logits corresponding to the start of the answer
|
|
end_logits: The logits corresponding to the end of the answer
|
|
"""
|
|
|
|
def __init__(self, unique_id, start_logits, end_logits, start_top_index=None, end_top_index=None, cls_logits=None):
|
|
self.start_logits = start_logits
|
|
self.end_logits = end_logits
|
|
self.unique_id = unique_id
|
|
|
|
if start_top_index:
|
|
self.start_top_index = start_top_index
|
|
self.end_top_index = end_top_index
|
|
self.cls_logits = cls_logits
|