Inspired by Learning Python from Ruby; Differences and Similarities.
I'm in the exact opposite boat - I'm pretty well-versed in Python, but I need to start learning Ruby soon (and Rails later, but that's another topic). The question I'm linking to addresses this a bit, but are there any other resources out there that teach Ruby for someone who already has Python experience? (In other words, someone with a background in programming, but who doesn't yet know the difference between code that IRB will execute properly and proper Ruby code.)
EDIT: I'm not just looking for a list of the differences between the two languages - I'm wondering if there are any guides/walkthroughs that are directed towards teaching Python programmers to write idiomatic Ruby. I know similar guides exist for migrating to Python from other languages, but I don't know about Ruby.