On 7/7/07, Travis Oliphant <[EMAIL PROTECTED]> wrote:
> > > On 7/6/07, *Travis Oliphant* <[EMAIL PROTECTED] > <mailto:[EMAIL PROTECTED]>> wrote: > > 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 > > > Do you have and idea off the top of your head head how painful this > would be from an implementation standpoint. And is there a theoretical > reason that it is important that the scalar and array implementations > match? I would think that, conceptually, they are all 1-bit integers, > and it seems that the 8-bit, versus 32- or 64-bits is just an > implementation detail. It would probably take about 2-3 hours to make the change and about 3 more hours to fix the problems that were not anticipated. Basically, we would have to special-case the bool like we do the unicode scalar (which also doesn't necessarily match the array-based representation but instead follows the Python implementation). I guess I don't really see a problem in switching just the numpy.bool_ scalar to be a sub-class of the Python bool type and adjusting the code to make the switch when creating a scalar.
Thanks for info. I'll put this on my list of things to look into, although it may take me a few weeks to get around to it, depending on how busy next week is. I don't see this as urgent, but it seems like a good change to make going forward. -- . __ . |-\ . . [EMAIL PROTECTED]
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