Interesting. I assumed that spending more time working with Python would be beneficial, but I guess it's not a big deal. This is great to know, as I've been resistant to starting with Ruby/Rails for the reason I described. Thanks!
Learning Ruby would give you a big leg up over starting from scratch learning Python.
I don't know if you are familiar with any programming languages at all, but many skills translate cross-language...the paradigms are the same. Particularly with Ruby & Python which are very similar languages. They're good at the same things, by and large.
Taking your Ruby skills over to Python will be a matter of "google: [python thing] in ruby".
For a specific example, Python has a unique thing called "list comprehensions". Using that google string you can get some great ideas about replicating that functionality in Ruby.
Anyway, on a grander scale, picking up new languages is the easy part of programming--even when they're not so similar.
I don’t do machine learning or data science, so I’m assuming here, but I would imagine whatever you end up doing would be en entirely different service than your web stack and could be whatever language you wanted.