[Python-Dev] Conditional expressions and sequences

[Skip Montanaro]

    Paul> Now in your new syntax this is essentially

    Paul> x = if condition then t else f

    Paul> Therefore it would be cool if the implementation was
    Paul> x=condition.__where__(t,f). This slot could be overwritten by
    Paul> classes like Numeric's array. If condition was a list this might
    Paul> be useful too.

Unfortunately, that requires both t and f to be evaluated.  In a NumPy
setting that's probably not a big deal because in most cases both values
will be used in the resulting output.  In a scalar context, the
short-circuit nature of the expression is often important.  If implemented
as any kind of function you've lost that capability.  

-- 
Skip Montanaro (skip@pobox.com)
http://www.mojam.com/
http://www.musi-cal.com/