[Cython] canonical way of converting numpy arrays to C arrays

[Dag Sverre Seljebotn]

Robert Kern wrote:
> Dag Sverre Seljebotn wrote:
> 
>> Comment: The only "shady" part here is "contarr.data", which accesses 
>> implementation details of NumPy arrays. I'm guessing that this will 
>> never change, but I once planned to make a generic cython function 
>> "cython.buffer.bufptr" which would return the same pointer but it could 
>> be acquired through the buffer API.
> 
> The canonical way to avoid accessing .data directly is to use the PyArray_DATA() 
> macro (returns a void*). Similarly, dimensions and strides can be accessed via 
> PyArray_DIMS() and PyArray_STRIDES().

Good point. (And I already do this for the buffer access in numpy.pxd, 
so the buffer access stuff is forwards-compatible with any change here.)

The reason I want cython.buffer.bufptr BTW is to have a common way of 
accessing similar pointers for all buffer exporters, not only NumPy arrays.

-- 
Dag Sverre