Testing NumPy with Cython

setup.py

from distutils.core import setup
from distutils.extension import Extension
from Cython.Build import cythonize
import numpy


ext_modules = cythonize([
    Extension("testnp",
              ["testnp.pyx"],
              include_dirs=[numpy.get_include()],
          )])


setup(name='testnp',
      ext_modules=ext_modules
)

testnp.pyx

import numpy as np
import h5py
import cython
cimport numpy as np

@cython.boundscheck(False)
@cython.wraparound(False)
def testnp(np.ndarray[double, ndim=3, mode="c"] data not None):

    cdef long dims[3]
    dims[0], dims[1], dims[2] = data.shape[0], data.shape[1], data.shape[2]
    fast_testnp(&data[0,0,0], &dims[0])


cdef int fast_testnp(double *data, long *dims):

    cdef double total
    cdef long iz, iy, ix

    total = 0
    for iz in range(dims[0]):
        for iy in range(dims[1]):
             for ix in range(dims[2]):
                 index = ix + dims[2]*iy + dims[2]*dims[1]*iz;
                 total += data[index];
    print(total)

    return 0