Hi,
This is with Python 3.8.2 64-bit and numpy 1.19.2 on Windows 10. I'd
like to be able to convert some C++ extension type to a numpy array by
using ``numpy.asarray``. The extension type implements the Python
buffer interface to support this.
The extension type, called "Image" here, holds some chunk of
``double``, C order, contiguous, 2 dimensions. It "owns" the buffer;
the buffer is not shared with other objects. The following Python
code crashes::
image = <... Image production ...>
ar = numpy.asarray(image)
However, when I say::
image = <... Image production ...>
print("---")
ar = numpy.asarray(image)
the entire program is executing properly with correct data in the
numpy ndarray produced using the buffer interface.
The extension type permits reading the pixel values by a method;
copying them over by a Python loop works fine. I am ``Py_INCREF``-ing
the producer in the C++ buffer view creation function properly. The
shapes and strides of the buffer view are ``delete[]``-ed upon
releasing the buffer; avoiding this does not prevent the crash. I am
catching ``std::exception`` in the view creation function; no such
exception occurs. The shapes and strides are allocated by ``new
Py_ssize_t[2]``, so they will survive the view creation function.
I spent some hours trying to figure out what I am doing wrong. Maybe
someone has an idea about this? I double-checked each line of code
related to this problem and couldn't find any mistake. Probabaly I am
not looking at the right aspect.
Best,
Friedrich
_______________________________________________
NumPy-Discussion mailing list
NumPy-Discussion@python.org
https://mail.python.org/mailman/listinfo/numpy-discussion
