Python is a general programming language. It can be used to develop and code a lot of things, from games to web applications and desktop software. R is a programming language you will only find in a data science environment.
If you are simply working with data science, then you should use R.
If, however, data science only happens to be one of the things you’re focused on, and you want the option of adapting your data and content to other mediums, then Python is the way to go.
Let’s say you are collecting a wide variety of data on your customers. You can work with this data — from a server and development approach — using either language.
If the data is simply going to stay data, and you are only going to look at the statistics, trends and patterns, then R is your best bet.
However, if you are going to take that data to develop a personalized product recommendation system for your website, for example, then Python will allow you to directly utilize the information and content you have, without starting from scratch.