NER-BERT-pytorch
PyTorch solution of Named Entity Recognition task with Google AI's BERT model.
利用Google AI的BERT模型进行中文命名实体识别任务的PyTorch实现。
Welcome to watch, star or fork.
MSRA dataset
Here, we take the Chinese NER data MSRA as an example. Of course, the English NER data is also fully applicable.
Named entity recognition task is one of the tasks of the Third SIGHAN Chinese Language Processing Bakeoff, we take the simplified Chinese version of the Microsoft NER dataset as the research object.
Data Formats
The NER dataset of MSRA consists of training set data/msra_train_bio
and test set data/msra_test_bio
, and no validation set is provided. There are 45000 training samples and 3442 test samples, and we will divide them appropriately later.
The dataset contains three types of entities: Person, Organization, Location and Other, the corresponding abbreviated tags are PER
, ORG
and LOC
and O
.
The format is similar to that of the Co-NLL NER task 2002, adapted for Chinese. The data is presented in two-column format, where the first column consists of the character and the second is a tag. The tag is specified as follows:
Tag | Meaning |
---|---|
O | Not part of a named entity |
B-PER | Beginning character of a person name |
I-PER | Non-beginning character of a person name |
B-ORG | Beginning character of an organization name |
I-ORG | Non-beginning character of an organization name |
B-LOC | Beginning character of a location name |
I-LOC | Non-beginning character of a location name |
B-GPE | Beginning character of a geopolitical entity |
I-GPE | Non-beginning character of a geopolitical entity |
Dataset patition
We randomly select 3000 samples from the training set as the validation set, and the test set is unchanged. Thus, the dataset distribution is as follows.
Dataset | Number |
---|---|
training set | 42000 |
validation set | 3000 |
test set | 3442 |
Requirements
This repo was tested on Python 3.5+ and PyTorch 0.4.1/1.0.0. The requirements are:
- tensorflow >= 1.11.0
- torch >= 0.4.1
- pytorch-pretrained-bert == 0.4.0
- tqdm
- apex
Note: The tensorflow library is only used for the conversion of pre-trained models from TensorFlow to PyTorch. apex is a tool for easy mixed precision and distributed training in Pytorch, please see https://github.com/NVIDIA/apex.
Results
We didn't search best parameters and obtained the following results.
Overall results
Based on the best performance of the model on the validation set, the overall effect of the model is as follows:
Dataset | F1_score |
---|---|
training set | 99.88 |
validation set | 95.90 |
test set | 94.62 |
Detail results on test set
Based on the best model on the validation set, we can get the recognition effect of each entity type on the test set.
NE Types | Precison | Recall | F1_score |
---|---|---|---|
PER | 96.36 | 96.43 | 96.39 |
ORG | 89.64 | 92.07 | 90.84 |
LOC | 95.92 | 95.13 | 95.52 |
Usage
-
Get BERT model for PyTorch
There are two ways to get the pre-trained BERT model in a PyTorch dump for your experiments :
-
Direct download of the converted pytorch version of the BERT model
You can download the pytorch dump I converted from the tensorflow checkpont from my Google Cloud Drive folder
bert-base-chinese-pytorch
, including the BERT parameters filebert_config.json
, the model filepytorch_model.bin
and the vocabulary filevocab.txt
. -
Convert the TensorFlow checkpoint to a PyTorch dump by yourself
-
Download the Google's BERT base model for Chinese from
BERT-Base, Chinese
(Chinese Simplified and Traditional, 12-layer, 768-hidden, 12-heads, 110M parameters), and decompress it. -
Execute the following command, convert the TensorFlow checkpoint to a PyTorch dump.
export TF_BERT_BASE_DIR=/path/to/chinese_L-12_H-768_A-12 export PT_BERT_BASE_DIR=/path/to/NER-BERT-pytorch/bert-base-chinese-pytorch pytorch_pretrained_bert convert_tf_checkpoint_to_pytorch \ $TF_BERT_BASE_DIR/bert_model.ckpt \ $TF_BERT_BASE_DIR/bert_config.json \ $PT_BERT_BASE_DIR/pytorch_model.bin
-
Copy the BERT parameters file
bert_config.json
and dictionary filevocab.txt
to the directory$PT_BERT_BASE_DIR
.cp $TF_BERT_BASE_DIR/bert_config.json $PT_BERT_BASE_DIR/bert_config.json cp $TF_BERT_BASE_DIR/vocab.txt $PT_BERT_BASE_DIR/vocab.txt
-
-
-
Build dataset and tags
python build_msra_dataset_tags.py
It will extract the sentences and tags from the dataset
data/msra_train_bio
anddata/msra_test_bio
, split them into train/val/test and save them in a convenient format for our model, and create a filetags.txt
containing a collection of tags. -
Set experimental hyperparameters
We created a
base_model
directory for you under theexperiments
directory. It contains a fileparams.json
which sets the hyperparameters for the experiment. It looks like{ "full_finetuning": true, "max_len": 180, "learning_rate": 3e-5, "weight_decay": 0.01, "clip_grad": 5, }
For every new experiment, you will need to create a new directory under
experiments
with aparams.json
file. -
Train and evaluate your experiment
if you use default parameters, just run
python train.py
Or specify parameters on the command line
python train.py --data_dir data/msra --bert_model_dir bert-base-chinese-pytorch --model_dir experiments/base_model --multi_gpu
It will instantiate a model and train it on the training set following the hyperparameters specified in
params.json
. It will also evaluate some metrics on the development set. -
Evaluation on the test set
Once you've run many experiments and selected your best model and hyperparameters based on the performance on the development set, you can finally evaluate the performance of your model on the test set.
if you use default parameters, just run
python evaluate.py
Or specify parameters on the command line
python evaluate.py --data_dir data/msra --bert_model_dir bert-base-chinese-pytorch --model_dir experiments/base_model