[Python-Dev] Proposal: Allow any mapping after ** in calls

Python allows arbitrary sequences after * in calls, but an expression following ** must be a (subclass of) dict. I believe * and ** should be treated similarly and since f(*UserList(..)) is valid, f(**UserDict(..)) should be valid as well. Of course, I can work around this limitation by writing f(**dict(UserDict(..))), but this is unnatural given that I don't have to do f(*tuple(UserList(..))). I have submitted a patch on SF that makes Python accept arbitrary mappings after **. See <https://sourceforge.net/tracker/?func=detail&atid=305470&aid=1686487&group_id=5470>.