On Sat, 3 Nov 2012 12:15:21 -0700, David Cortesi <davecort...@gmail.com> wrote: > Following up on a stackoverflow answer re manipulating > a QImage, I access the contents of an image by: > > vptr = myQi.bytes() > vptr.setsize(myQi.byteCount()) > > Per the Riverbank docs, > >> A sip.voidptr may also be given a size... If it has a size then it is >> also able to support Python’s buffer protocol and behaves just >> like a Python memoryview object...
I've removed the word "just" as I didn't mean to imply they had the same APIs. > Not being familiar with memoryview I read the docs, > http://docs.python.org/2.7/library/stdtypes.html#memoryview-type > but I find that my voidptr made as above, does not support any of the > members that type memoryview is supposed to have, such as > readonly(), strides(), ndim(), itemsize(), and especially, > tobytes(). All produce AttributeError. > > I can access one byte with vptr[i], but a slice vptr[0:8] > produces only another voidptr object. In the same way that a slice of a memoryview returns another memoryview. > When I try assignment, > vptr[1] = 0x00 > I get the message, > TypeError: 'int' does not have the buffer interface > > Clearly there is something I don't get about voidptr and its uses. > > This is with python 2.7.6 on ubuntu 12.10, and whatever > levels of Qt4 and PyQt4 I just downloaded with synaptic today. I can't reproduce this - can you send a short, complete test that demonstrates the problem. In tonight's sip snapshot you will be able to pass any object that implements the Python buffer protocol to sip.voidptr() (like a bytearray). If nothing else this makes it easier to write tests for voidptr. Phil _______________________________________________ PyQt mailing list PyQt@riverbankcomputing.com http://www.riverbankcomputing.com/mailman/listinfo/pyqt
