Learning a programming language is a required step for most data scientist positions. Data scientists generally don’t do all types of software programming—most won’t be doing front-end work (like web development). Instead, data scientists usually work the most with scripts or notebooks that are single files. If you have to do your own productionizing, you’ll probably also sometimes design multi-file software to carry out your modeling, and you may use other tools to take your code into production. Python and R are the two most common languages used by data scientists, and this chapter will introduce the basics of programming in common languages like these, as well as look a bit at how these two are different.