Do data scientists learn both Python and R? Or do they just focus on one?

Some learn one, others learn both. This Udacity post covers the language choice dilemma nicely. Martijn Theuwissen (co-founder of DataCamp) explains how learning both can be beneficial here.

I chose to learn both. I might focus on one later, but I’m keeping my options open until I complete this machine learning book (which uses R) and a few courses (which use Python).