I've been considering the same thing as you and I haven't reached any decision, but maybe I can add my impressions. Ruby and Rails does seem to be better targe

I've been considering the same thing as you and I haven't reached any decision, but maybe I can add my impressions. Ruby and Rails does seem to be better targeted for web development, both because (as some here have said) Rails is more meaty than Django and because there seem to be many more web development jobs out there requiring RoR. Python on the other hand seems like a much better general purpose programming language, with a far richer set of libraries (ScyPy and NumPy on which Sage Math is based, bindings for wxWidgets and other toolkits etc)