[Numpy-discussion] comparing string array with None raises ValueError

David M. Cooke cookedm at physics.mcmaster.ca
Thu Jun 24 22:45:16 CDT 2004

On June 24, 2004 04:10 pm, Todd Miller wrote:
> On Thu, 2004-06-24 at 15:26, David M. Cooke wrote:
> > On June 24, 2004 01:46 pm, Sebastian Haase wrote:
> > > In general it must be OK to compare anything with None, right ?
> > > (BTW, I get the same error with == and !=)
> >
> > No! Not in general!
> Well,  this is a good point.  I think the current numerical behavior was
> a hack I stuck in for people who might not be aware of "is".  It's
> looking like a mistake now.

I've fixed up all uses of == None and != None in my copy of the numarray CVS, 
but the anonymous CVS on SourceForge is timing out :-(, so I haven't made a 
patch yet. Basically, I ran 'grep -R "[!=]= *None" *' to find all uses of == 
and != None, and replaced them with is/is not None. That would remove 
possible bugs.

|David M. Cooke                      http://arbutus.physics.mcmaster.ca/dmc/
|cookedm at physics.mcmaster.ca

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