Python is a popular programming language that data scientists use, particularly for machine learning or predictive tasks. R is also popular, especially for statistically-oriented tasks, or those with research and academic backgrounds. Often, large technology companies predicate which languages are the most popular to use merely through adopting it and institutionalizing it. Google is heavily invested in Python, for example, from using it for their own purposes as well as creating libraries that do very specific tasks that they have open-sourced, like TensorFlow. So, in that way, Python becomes a good language to know if data scientists are working with Google products.