我从cython.group在Google中获得的答案非常有效：

An answer which I got from cython.group in google works perfectly:

import cython
cimport cython

import numpy as np
cimport numpy as np

DTYPE = np.float64
ctypedef np.float64_t DTYPE_t

cdef class halo_positions(object):

    cdef double [:] _x
    property x:
        def __get__(self):
            return np.array(self._x)
        def __set__(self, np.ndarray[DTYPE_t, ndim=1] x):
            self._x = x

    cdef double [:] _y
    property y:
        def __get__(self):
            return np.array(self._y)
        def __set__(self, np.ndarray[DTYPE_t, ndim=1] y):
            self._y = y

    def __init__(self, np.ndarray[DTYPE_t,ndim=2] positions):
        self._x = positions[:,0]
        self._y = positions[:,1]

    def debug(self):
        print self.x, self.y