PR #3108 (originally) tried to make float a subclass of numbers.Real. Two method implementations were missing, __floor__ and __ceil__ (cpython). These do exist for int and Decimal etc., but @srittau noticed that they actually do not exist for float itself, therefore they cannot be added to float's stubs, and float cannot be made to conform to numbers.Real.

I did some digging and found that abstractly numbers.Real really just wants math.floor() and math.ceil() to work. And in cpython, these two functions work something like this (using floor ):

1. If the argument is a float, do the operation directly in C code.
2. Else, if the argument has a __floor__ method, use it.
3. Else, if the argument has a __float__ method, use it and go to (1).

As it happen, numbers.Real does require __float__() to be implemented. So as a workaround for this issue, I proposed removing __floor__ and __ceil__ from typeshed's numbers.Real stub, since the __float__ fallback can be relied on instead.

Another view is that this is a cpython issue and should be fixed there.

And another view is that numbers is a lost cause for static typing and should just be ignored or replaced with something better (like protocols).