On 5/2/2010 4:34 AM, Carl Banks wrote:
Why don't you use mysubtype.__new__(mysubtype,...)?
If you wrote mysubtype in C, and defined a different tp_new than
ndarray, then this exception will trigger. And it ought to; you don't
want to use ndarray's tp_new to create an object of your subclass, if
you've defined a different tp_new.
Unfortunately, I can't do that, since that call is in NumPy itself and
it's part of their "standard" way of making instances of subclasses of
ndarray. Functions like numpy.zeros_like use ndarray.__new__(subtype,
...) to create new arrays based on the shape of other arrays.
The Python version of the subclass is shown here:
<http://docs.scipy.org/doc/numpy/user/basics.subclassing.html#slightly-more-realistic-example-attribute-added-to-existing-array>,
and I'm trying to write something pretty similar in C. I'm trying to
stay in C since everything else is in C, so it's easier to stay in C
then to jump back and forth all the time.
Maybe the real answer to this question is "NumPy is doing it wrong" and
I should be on their list; still, it seems strange that the behavior is
different between Python and C.
- Jim
--
http://mail.python.org/mailman/listinfo/python-list
