Ruby lover here. I can code Ruby while I sleep, but I felt a bit left out because there are so many awesome Python projects.
In comparison, there's Rails as awesome Ruby project with a lot of momentum, and .... that's about it.
With Ruby knowledge, it's actually pretty easy to grasp Python. There are a few gotchas and the syntax feels a bit boring compared to Ruby, but it's also easier to read other people's code because it's usually more explicit and a bit less dynamic than Ruby.
I still love Ruby, but it's good to be able to write a few lines of Python and release the power of Numpy/Pandas/Sympy/Matplotlib/NetworkX/... It took me about 2 weeks to learn enough Python to use those libraries, and I still learn new stuff every day.
Some parts of Python's syntax are really nice, e.g. list comprehension :
>>> [x**2 for x in range(10) if x % 2 == 1]
[1, 9, 25, 49, 81]
It's completely different than all the Enumerable methods in Ruby, but it's very powerful and quite easy to read after a while.