Python Tutorial: Introduction to regular expressions

Want to learn more? Take the full course at https://learn.datacamp.com/courses/introduction-to-natural-language-processing-in-python at your own pace. More than a video, you'll learn hands-on coding & quickly apply skills to your daily work. --- Welcome to the course! In this video, you'll be learning about regular expressions. Natural language processing is a massive field of study and actively used practice which aims to make sense of language using statistics and computers. In this course, you will learn some of the basics of NLP which will help you move from simple to more difficult and advanced topics. Even though this is the first course, you will still get some exposure to the challenges of the field such as topic identification and text classification. Some interesting NLP areas you might have heard about are: topic identification, chatbots, text classification, translation, sentiment analysis. There are also many more! You will learn the fundamentals of some of these topics as we move through the course. Regular expressions are strings you can use that have a special syntax, which allows you to match patterns and find other strings. A pattern is a series of letters or symbols which can map to an actual text or words or punctuation. You can use regular expressions to do things like find links in a webpage, parse email addresses and remove unwanted strings or characters. Regular expressions are often referred to as regex and can be used easily with python via the `re` library. Here we have a simple import of the library. We can match a substring by using the re.match method which matches a pattern with a string. It takes the pattern as the first argument, the string as the second and returns a match object, here we see it matched exactly what we expected: abc. We can also use special patterns that regex understands, like the \w+ which will match a word. We can see here via the match object representation that it has matched the first word it found --