def zip(self):
return numpy.column_stack((self.xindex.value, self.value))<EOL>
Zip the `xindex` and `value` arrays of this `Series`

        Returns
        -------
        stacked : 2-d `numpy.ndarray`
            The array formed by stacking the the `xindex` and `value` of this
            series

        Examples
        --------
        >>> a = Series([0, 2, 4, 6, 8], xindex=[-5, -4, -3, -2, -1])
        >>> a.zip()
        array([[-5.,  0.],
               [-4.,  2.],
               [-3.,  4.],
               [-2.,  6.],
               [-1.,  8.]])