I'm not sure I follow your meaning here. You can return unnamed lists, dictionaries, numbers, among others, or combinations of any of these. With some very light syntax sugar magic you can even make returning tuples look like your returning multiple values.

I'm not sure if I would call whitespace-as-syntax arbitrary, though it is opinionated. I admit though that for me it started feeling like a time saver once I got over my anti whitespace as syntax zealotry.