Before deep learning and statistical modeling took over, NLP was all about rules. That's not to say that rule-based systems are dead! They are often easy to set up and perform very well when it comes to doing simple tasks.
Imagine you wanted to find all mentions of Google in a text. Would you really train a neural network-based named entity recognizer? If you did, you would have to run all of the text through the neural network and then look for Google in the entity texts. Alternatively, would you rather just search for text that exactly matches Google with a classic search algorithm? Well, we're in luck, as spaCy comes with an easy-to-use, rule-based matcher that allows us to do just that.
Before we start this section, we first ...