Further reading

• NLTK sentiment analysis example: https://www.nltk.org/howto/sentiment.html
• The source code for VADER and its documentation: https://github.com/cjhutto/vaderSentiment
• Bayes theorem explained: https://plato.stanford.edu/entries/bayes-theorem/
• VADER sentiment analysis research: http://comp.social.gatech.edu/papers/icwsm14.vader.hutto.pdf