On Wed, Jan 31, 2018 at 3:25 PM, Jialin Liu <jalnliu@lbl.gov> wrote:
I'm extending C with python (which is opposite way of what people usually do, extending python with C), I'm currently stuck in passing a C array to python layer, could anyone plz advise?

I have a C buffer in my C code and want to pass it to a python function. In the C code, I have:

npy_intp  dims [2];
dims[0] = 10;
dims[1] = 20; 
npy_intp m=2;
PyObject * py_dims = PyArray_SimpleNewFromData(1, &m, NPY_INT16 ,(void *)dims ); // I also tried NPY_INT
PyObject_CallMethod(pInstance, method_name, "O", py_dims);
In the Python code, I want to just print that array:

def f(self, dims):

   print ("np array:%d,%d"%(dims[0],dims[1]))

But it only prints the first number correctly, i.e., dims[0]. The second number is always 0. 

The correct typecode would be NPY_INTP.

Robert Kern