Programming languages used for machine learning depend on your requirements and expected predictions. MATLAB, R, and Python are commonly used languages because of their ability to provide powerful functions for statistical analysis.
If you want to explore and write your own machine learning algorithms, you might want to learn these languages; however, to use Einstein, PredicitonIO, or any other topic discussed in this book does not require you to know R or Python. Instead, we will keep it simple with Apex, Java, Scala, or Node that most of the developers are already familiar with.