Sentiment analysis is part of the Natural Language Processing (NLP) techniques that consists in extracting emotions related to some raw texts. This is usually used on social media posts and customer reviews in order to automatically understand if some users are positive or negative and why. The goal of this study is to show how sentiment analysis can be performed using python. Here are some of the main libraries we will use: NLTK: the most famous python module for NLP techniques Gensim: a topic-modelling and vector space modelling toolkit Scikit-learn: the most used python machine learning library We will use here some hotel reviews data. Each observation consists in one customer review for one hotel. Each customer review is composed of a textual feedback of the customer's experience at the hotel and an overall rating