If you only need 5 kwargs, reading 5 elements from a 500k element dict is O(1). Just finding the max index is O(n). You might be right that even passing 500k el

If you only need 5 kwargs, reading 5 elements from a 500k element dict is O(1). Just finding the max index is O(n). You might be right that even passing 500k element dict to a function **kwargs has terrible performance today anyway (I haven't checked but it does sound plausible from your timing tests). It seems like we are now looking for imprecisions in each other's reply and discussion does not seem to be constructive: we are agreeing on rough potential implementations, it's just that we differ whether that should be acceptable or not. That's fine, you are not convincing me and I am not convincing you, so we might as well drop it. It's not like this proposal is happening :) Have a good day!