check if object is number

[Steven Bethard]

Peter Hansen wrote:
> Of course, most of the other definitions of "is a number" that
> have been posted may likewise fail (defined as not doing what the
> OP would have wanted, in this case) with a numarray arange.
> Or maybe not.  (Pretty much all of them will call an arange a
> number... would the OP's function work properly with that?)

No, but it will fail properly since my code basically looks like:

def f(max=None):
     ...
     while max is None or n <= max:
         ...
         # complicated incrementing of n

So if max is an array, though all of the proposed isnumber checks will 
call it a number, my code will (rightly) fail when the array (n <= max) 
gets __nonzero__ called in the while condition.  I guess I'd prefer it 
to fail in the isnumber check, but overall, I'm more concerned that 
_some_ error is produced, not necessarily which one.  (I'm also not 
thrilled that bool(array) raises a RuntimeError instead of a TypeError...)

Steve