Python and Ruby seem very similar. This is part of the reason holy wars erupt between the groups so easily. Ruby on Rails has been a skill in demand for a while, but then, so is Django. For the most part I would say that Python and Ruby accomplish essentially the same things, and to a degree have the same advantages and disadvantages. You will probably learn it fairly easily if you are comfortable with Python. I only looked into it glancingly but it seemed it would be pretty easy to pick up.
You might find this book amusing:http://mislav.uniqpath.com/poignant-guide/