def _py_flattened_idx(self):
    return '+'.join([('neigh_strides[%d]*neigh_idx_%d' % (i, i)) for i in xrange(len(self.strides))])
def _py_flattened_idx(self):
    return '+'.join([('neigh_strides[%d]*neigh_idx_%d' % (i, i)) for i in xrange(len(self.strides))])