Python is a fairly general language, and can be used for many different things. R is pretty specifically designed for statistical analysis.
So, the answer depends on what you're hoping to get out of it. If your only concern is employability in your specific field, it might make sense to look into the sorts of companies where you're hoping to work, and see which languages are used most commonly there. If you're concerned about employability more generally, Python would probably open more doors for you than R would, in a wider variety of companies and industries. If you want to learn some basic programming, Python will definitely give you a better sense of how software works, generally, and allow you to write a much wider variety of programs. If you specifically want to do statistical analysis, R is custom built for that task, and is probably the better choice.
If none of the above apply to you, or if you're just not sure about the answers, I would recommend Python. That language will be useful in the widest range of situations, and is something you might find valuable no matter what kind of job you eventually end up in. R is a much more specialized tool, and is only really useful for statistical analysis. Learning Python is like getting a hammer, and learning R is like getting one of those funny shaped screwdrivers. When you need that funny screwdriver, it's definitely the tool you want, but most people never need one. Everybody wants a hammer sometimes, though.