[Python-Dev] PyObject_RichCompareBool identity shortcut (original) (raw)

Stephen J. Turnbull stephen at xemacs.org
Thu Apr 28 04:42:30 CEST 2011

Mark Dickinson writes:

Declaring that 'nan == nan' should be True seems attractive in theory,

No, it's intuitively attractive, but that's because humans like nice continuous behavior. In theory, it's true that some singularities are removable, and the NaN that occurs when evaluating at that point is actually definable in a broader context, but the point of NaN is that some singularities are not removable. This is somewhat Pythonic: "In the presence of ambiguity, refuse to guess."

More information about the Python-Dev mailing list