[Numpy-discussion] Should bool_ subclass int?

Travis Oliphant oliphant.travis at ieee.org
Sat Jul 7 01:45:01 EDT 2007

Timothy Hochberg wrote:
> I'm working on getting some old code working with numpy and I noticed 
> that bool_ is not a subclass of int. Given that python's bool 
> subclasses into and that the other scalar types are subclasses of 
> their respective counterparts it seems at first glance that 
> numpy.bool_ should subclass python's bool, which in turn subclasses 
> int. Or am I missing something here?
The reason it is not, is because it is not binary compatible with 
Python's integer.   The numpy bool_ is always only 8-bits while the 
Python integer is 32-bits or 64-bits.

This could be changed I suspect, but then it would break the 
relationship between scalars and their array counterparts and I'm sure 
we would not want to bump up all bool arrays to 32 or 64-bits.


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