Steven D'Aprano <st...@pearwood.info> writes: > Robert Kern wrote: > > On 4/28/11 8:44 PM, Steven D'Aprano wrote: > >> The real question should be, why does Python treat all NANs as > >> signalling NANs instead of quiet NANs? I don't believe this helps > >> anyone. > > > > Actually, Python treats all NaNs as quiet NaNs and never signalling NaNs. > > Sorry, did I get that backwards? I thought it was signalling NANs that > cause a signal (in Python terms, an exception)? > > If I do x = 0.0/0 I get an exception instead of a NAN. Hence a > signalling NAN.
Robert has interpreted your “treats all NaNs as signalling NaNs” to mean “treats all objects that Python calls a NaN as signalling NaNs”, and is pointing out that no, the objects that Python calls “NaN” are all quiet NaNs. You might be clearer if you distinguish between what Python calls a NaN and what you call a NaN. It seems you're saying that some Python exception objects (e.g. ZeroDivisionError objects) are what you call NaNs, despite the fact that they're not what Python calls a NaN. -- \ “We can't depend for the long run on distinguishing one | `\ bitstream from another in order to figure out which rules | _o__) apply.” —Eben Moglen, _Anarchism Triumphant_, 1999 | Ben Finney _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
