numpy-discussion

[Numpy-discussion] Fastest way of distinguish a numpy scalar of a python scalar?

[Francesc A. <fa...@ca...>]

Hi,

I thought that numpy.isscalar was a good way of distinguising a numpy scala=
r=20
from a python scalar, but it seems not:

>>> numpy.isscalar(numpy.string_('3'))
True
>>> numpy.isscalar('3')
True

Is there an easy (and fast, if possible) way to check whether an object is =
a=20
numpy scalar or a python one?

Thanks,

=2D-=20
>0,0<   Francesc Altet =A0 =A0 http://www.carabos.com/
V   V   C=E1rabos Coop. V. =A0=A0Enjoy Data
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Re: [Numpy-discussion] Fastest way of distinguish a numpy scalar of a python scalar?

[Sebastian H. <ha...@ms...>]

Hi,
a noticed the underscore in "numpy.string_"  ...
I thought the underscores were removed in favour of handling the 
"from numpy import *" separately via the __all__ variable.
Is this done only for *some* members of numpy ?

(sorry for hijacking your thread ...)
-Sebastian Haase




On Tuesday 03 October 2006 09:55, Francesc Altet wrote:
> Hi,
>
> I thought that numpy.isscalar was a good way of distinguising a numpy
> scalar
>
> from a python scalar, but it seems not:
> >>> numpy.isscalar(numpy.string_('3'))
>
> True
>
> >>> numpy.isscalar('3')
>
> True
>
> Is there an easy (and fast, if possible) way to check whether an object is
> a numpy scalar or a python one?
>
> Thanks,

Re: [Numpy-discussion] Fastest way of distinguish a numpy scalar of a python scalar?

[Travis O. <oli...@ee...>]

Sebastian Haase wrote:

>Hi,
>a noticed the underscore in "numpy.string_"  ...
>I thought the underscores were removed in favour of handling the 
>"from numpy import *" separately via the __all__ variable.
>Is this done only for *some* members of numpy ?
>  
>
Yeah.  The underscores are still on the conflicting type names.

-Travis

Re: [Numpy-discussion] Fastest way of distinguish a numpy scalar of a python scalar?

[Tim H. <tim...@ie...>]

Francesc Altet wrote:
> Hi,
>
> I thought that numpy.isscalar was a good way of distinguising a numpy scalar 
> from a python scalar, but it seems not:
>
>   
>>>> numpy.isscalar(numpy.string_('3'))
>>>>         
> True
>   
>>>> numpy.isscalar('3')
>>>>         
> True
>
> Is there an easy (and fast, if possible) way to check whether an object is a 
> numpy scalar or a python one?
>
>   
It looks like isinstance(x, numpy.generic) works, but I didn't test it 
extensively.

-tim

Re: [Numpy-discussion] Fastest way of distinguish a numpy scalar of a python scalar?

[Travis O. <oli...@ee...>]

Tim Hochberg wrote:

>Francesc Altet wrote:
>  
>
>>Hi,
>>
>>I thought that numpy.isscalar was a good way of distinguising a numpy scalar 
>>from a python scalar, but it seems not:
>>
>>  
>>    
>>
>>>>>numpy.isscalar(numpy.string_('3'))
>>>>>        
>>>>>          
>>>>>
>>True
>>  
>>    
>>
>>>>>numpy.isscalar('3')
>>>>>        
>>>>>          
>>>>>
>>True
>>
>>Is there an easy (and fast, if possible) way to check whether an object is a 
>>numpy scalar or a python one?
>>
>>  
>>    
>>
>It looks like isinstance(x, numpy.generic) works, but I didn't test it 
>extensively.
>
>  
>
That should definitely work. All the array scalars are in a hierarchy 
inheriting from numpy.generic.  There are also sub-levels 
(numpy.integer, numpy.inexact, etc...)


-Travis