Bruce Leban writes:
(Personally, I would have made them non-hashable so you couldn't accidentally stick one in a dict but that's another problem.)
No, it's not. AIUI, that is one of the main issues that's being discussed in this thread. Most people seem reasonably satisfied with other behavior, so the discussion bounces back and forth between whether NaNs should be hashable (and, perhaps more often, whether they should all be equal or not), and how any change in identity or equality behavior might affect computations in existing programs.