As already pointed out, one is a framework (RoR), while the other is a language. As you talk of learning a programming language, I'm guessing you meant, should

As already pointed out, one is a framework (RoR), while the other is a language. As you talk of learning a programming language, I'm guessing you meant, should I choose Ruby or Python? To pick between I would suggest you try and write a couple of simple scripts in both and see which suits you better. You should also think what you would like to use this knowledge for in the future. Do you want to build web apps, manipulate text, write desktop apps? Once you know this, it'll be easier to make the right choice about which tech to use.