[Python-Dev] Re: PyNumber_Check()

[Guido van Rossum]

> gvanrossum@projects.sourceforge.net wrote:
> > *** NEWS	18 Nov 2002 16:19:39 -0000	1.526
> > --- NEWS	18 Nov 2002 16:27:16 -0000	1.527
> > ***************
> > *** 694,698 ****
> >   - PyNumber_Check() now returns true for string and unicode objects.
> >     This is a result of these types having a partially defined
> > !   tp_as_number slot.
> >   
> >   - The string object's layout has changed: the pointer member
> > --- 694,700 ----
> >   - PyNumber_Check() now returns true for string and unicode objects.
> >     This is a result of these types having a partially defined
> > !   tp_as_number slot.  (This is not a feature, but an indication that
> > !   PyNumber_check() is not very useful to determine numeric behavior.
> > !   It may be deprecated.)
> 
> Perhaps PyNumber_Check() should check that at least
> one of nb_int, nb_long, nb_float is available (in addition to the
> tp_as_number slot) ?!

No, I think PyNumber_Check() should be deprecated.  I don't think
there's a valid use case for it.  If you really want a fuzzy
definition like "at least one of nb_int, nb_long, nb_float is
available", you can test for that yourself -- IMO that doesn't really
make it a number.

PyNumber_Check() comes from an old era, when the presence or absence
of the as_number "extension" to the type object was thought to be
useful.  If I had to do it over, I wouldn't provide PyNumber_Check()
at all (nor PySequence_Check() nor PyMapping_Check()).

--Guido van Rossum (home page: http://www.python.org/~guido/)