[Numpy-discussion] please comment on scalar types

Travis Oliphant oliphant.travis at ieee.org
Mon Aug 14 20:18:04 CDT 2006


Sebastian Haase wrote:
> Hi!
> I have a record array with a field 'mode'
> Mode is a small integer that I use to choose a "PixelType"
> So I did:
>   
>>>> print PixelTypes[ mode ]
>>>>         
> TypeError: tuple indices must be integers
>   
>>>> pdb.pm()
>>>>         
>> /home/haase/PrLinN64/Priithon/Mrc.py(813)MrcMode2numType()
>>     
> -> return PixelTypes[ mode ]
> (Pdb) p mode
> 1
> (Pdb) p type(mode)
> <type 'int32scalar'>
> (Pdb) p isinstance(mode, int)
> False
>
> Since numpy introduced special scalar types a simple statement like this 
> doesn't work anymore !  Would it work if int32scalar was derived from int ? I 
> actually thought it was ...
>   
It does sub-class from int unless you are on a system where a c-long is 
64-bit then int64scalar inherits from int.

On my 32-bit system:

isinstance(array([1,2,3])[0],int)  is true.



-Travis





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