Terry: Thanks for your example use case. I hope that Raymond would be convinced.

I take your point regarding summarizing the discussion, sorry about that. 

Regarding me writing a test: I'm only willing to write code for a feature for Python if there's general interest from python-dev in getting said feature into Python. If there's general agreement from core python-dev members that this feature should be implemented, I'll be happy to do my part and write the test. But otherwise... I really have better things to do than spending my time writing code that will never be used, especially when it'll take me 10x more time to write it than a python-dev member because 90% of the work would be making the test case comply to the development practices of CPython, and only 10% of it would be to write the actual simple logic.