You can use ctypes
's c_short
and POINTER
to help with the intermediate conversion. The following function turns a numpy array into a C-type 2darray that can be passed into a C function expecting a short **
.
def c_short_2darr(numpy_arr):
c_short_p = POINTER(c_short)
arr = (c_short_p * len(numpy_arr) ) ()
for i in range(len(numpy_arr)):
arr[i] = (c_short * len(numpy_arr[i]))()
for j in range(len(numpy_arr[i])):
arr[i][j] = numpy_arr[i][j]
return arr
Note, I modified func_py
and CPPClass::func
to take 2 extra parameters, width and length of the given array. With this, CPPClass::func
can print out all of elements of the array:
// ...
void CPPClass::func(unsigned short **array, size_t w, size_t h)
{
for(size_t i = 0; i < w; ++i)
{
for(size_t j = 0; j < h; ++j)
cout << array[i][j] << ", ";
cout << '\n';
}
}
// ...
void func_py(CPPClass *myClass,
unsigned short **array,
size_t w, size_t h)
{
myClass->func(array, w, h);
}
With that helper function defined, the following should now work:
>>> arr = numpy.array([ [1,2,3], [4,5,6] ])
>>> arr
array([[1, 2, 3],
[4, 5, 6]])
>>> cpplib.func_py(cppobj, c_short_2darr(arr), 2, 3)
1, 2, 3,
4, 5, 6,
0