This repository is based on the Pytorch-Transformers library by HuggingFace. It is intended as a starting point for anyone who wishes to use Transformer models in text classification tasks.

Please refer to this Medium article for further information on how this project works.

• Setup
  • Very quickstart
  • With Conda
• Usage
  • Yelp Demo
  • Custom Datasets
  • Current Pretrained Models
  • Evaluation Metrics
• Acknowledgements

Try this Google Colab Notebook for a quick preview. You can run all cells without any modifications to see how everything works. However, due to the 12 hour time limit on Colab instances, the dataset has been undersampled from 500 000 samples to about 5000 samples. For such a tiny sample size, everything should complete in about 10 minutes.

1. Install Anaconda or Miniconda Package Manager from here
2. Create a new virtual environment and install packages.
   conda create -n transformers python pandas tqdm jupyter
conda activate transformers
   If using cuda:
   conda install pytorch cudatoolkit=10.0 -c pytorch
   else:
   conda install pytorch cpuonly -c pytorch
conda install -c anaconda scipy
conda install -c anaconda scikit-learn
pip install pytorch-transformers
3. Clone repo. git clone https://github.com/ThilinaRajapakse/pytorch-transformers-classification.git

This demonstration uses the Yelp Reviews dataset.

Linux users can execute data_download.sh to download and set up the data files.

If you are doing it manually;

1. Download Yelp Reviews Dataset.
2. Extract train.csv and test.csv and place them in the directory data/.

Once the download is complete, you can run the data_prep.ipynb notebook to get the data ready for training.

Finally, you can run the run_model.ipynb notebook to fine-tune a Transformer model on the Yelp Dataset and evaluate the results.

The table below shows the currently available model types and their models. You can use any of these by setting the model_type and model_name in the args dictionary. For more information about pretrained models, see HuggingFace docs.

When working with your own datasets, you can create a script/notebook similar to data_prep.ipynb that will convert the dataset to a Pytorch-Transformer ready format.

The data needs to be in tsv format, with four columns, and no header.

This is the required structure.

• guid: An ID for the row.
• label: The label for the row (should be an int).
• alpha: A column of the same letter for all rows. Not used in classification but still expected by the DataProcessor.
• text: The sentence or sequence of text.

The evaluation process in the run_model.ipynb notebook outputs the confusion matrix, and the Matthews correlation coefficient. If you wish to add any more evaluation metrics, simply edit the get_eval_reports() function in the notebook. This function takes the predictions and the ground truth labels as parameters, therefore you can add any custom metrics calculations to the function as required.

None of this would have been possible without the hard work by the HuggingFace team in developing the Pytorch-Transformers library.