Just to cut this thread short, I'm going to reject PEP 505, because ? is just too ugly to add to Python IMO. Sorry. I commend Mark for his clean write-up, without being distracted, giving some good use cases. I also like that he focused on a minimal addition to the language and didn't get distracted by hyper-generalizations. I also like that he left out f?(...) -- the use case is much weaker; usually it's the object whose method you're calling that might be None, as in title?.upper(). Some nits for the PEP: - I don't think it ever gives the priority for the ?? operator. What would "a ?? b or c" mean? - You don't explain why it's x ?? y but x ?= y. I would have expected either x ? y or x ??= y. - You don't explain or show how far ?. reaches; I assume x?y.z is equivalent to None if x is None else x.y.z, so you don't have to write x?.y?.z just to handle x.y.z if x is None. - The specification section is empty. -- --Guido van Rossum (python.org/~guido)