SPELL CHECKER deployed as a REST API using Flask

Classical probabilistic approaches have dominated spell checkings. This project uses a deep learning based approach to suggest upto three correct spelling recommendations for any given word.

Dataset for training

Web Inventory of Transcribed and Translated Talks; it is a ready-to-use version for research purposes of the multilingual transcriptions of TED talks.

Model architecture

The network architecture makes use of the architecture FastText, developed by Facebook. It has the advantage of traditional word vectors like Glove, word2vec etc in the sense that it can produce word vectors even for out-of-sample words. Also, for rare words it has been found be much more impactful than word vector representations.

Every word is represented in a 100-dimensional feature space and the model is trained on the data with window_size=5 and min_count=5 with the help of gensim library. The trained model contains 100-D representation of all possible unique characters of the training dataset.

Procedure

• Start a virtual environment and install requirements
• Run the file model.py. This will download your training data as well as train the FastText model on it, learn the representations and save them as model.bin
• Write app.py which is the API application that will be deployed
• Test the API

Testing the API

1. Run the Flask API locally for testing. Go to directory with app.py

python app.py

This outputs

  * Serving Flask app "app" (lazy loading)
  * Environment: production
  * WARNING: Do not use the development server in a production environment.
  * Use a production WSGI server instead.
  * Debug mode: on
  * Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)
  * Restarting with stat
  * Debugger is active!
  * Debugger PIN: 154-300-115

2. Using curl in a new terminal to make a GET request at the URL of the API

curl -X GET http://127.0.0.1:5000/spellCorrect -d query='sellection'

3. Example of successful output

{
    "prediction": [
        "selection"
    ]
}

References

• Peter Norvig's famous blog post on spelling correction
• A recent deep learning based approach for spelling correction