[Numpy-discussion] Should bool_ subclass int?

Alan G Isaac aisaac@american....
Sat Jul 7 14:02:20 CDT 2007


On Sat, 7 Jul 2007, Charles R Harris apparently wrote: 
> In [60]: a 
> Out[60]: array([ True,  True,  True,  True], dtype=bool) 
> In [61]: a + a 
> Out[61]: array([ True,  True,  True,  True], dtype=bool) 

Yea!
Behaves like a boolean array.
And for multiplication to.
And in boolean matrices, powers work right.
(I use this.)


> In [62]: a + 1 
> Out[62]: array([2, 2, 2, 2]) 

Yea!
Coercion to int, as expected.


> In [66]: True + True 
> Out[66]: 2 

Boo!
Hopefully Python will "fix" this one day.

Cheers,
Alan Isaac




More information about the Numpy-discussion mailing list