Here's another str.split() suggestion, this time an extension (Pythonic, I think) rather than a change of semantics. There are cases where, especially in handling user input, I'd like to be able to treat any of a series of possible delimiters as acceptable. Let's say that I want commas, underscores, and hyphens to all be treated as delimiters (as I did in some code I was writing today). I guessed, based on some other Python std lib behaviours, that this might work: usertokens = userstr.split([",", "_", "-"]) It doesn't work though, since the sep argument *has* to be a string. I think it would be nice for an extension like this to be supported, although I would guess a 90% probability of there being an insightful reason for why it's not such a great idea after all* ;-) Unlike many extensions, I don't think that the general solution to this is *very* quick and idiomatic in current Python. As for a compelling use-case... well, I'm very sympathetic to not adding functions for which there is no demand (I forget the relevant acronym) but this is a case where I suddenly found that I did have that problem to solve and that Python didn't have the nice built-in answer that I semi-expected it to. Extension of single arguments to iterables of them is quite a common Python design feature: one of those things where you think "ooh, this really is a nice, consistent, powerful language" when you find it. So I hope that this suggestion finds some favour. Best wishes, Andy [*] Such as "how do you distinguish between a string, which is iterable over its characters, and a list/tuple/blah of individual strings?" Well, that doesn't strike me as too big a technical issue, but maybe it is.