test_dtypes.py 文件源码

def test_astype_datetimes(self):
        import pandas.tslib as tslib

        s = Series(tslib.iNaT, dtype='M8[ns]', index=lrange(5))
        s = s.astype('O')
        self.assertEqual(s.dtype, np.object_)

        s = Series([datetime(2001, 1, 2, 0, 0)])
        s = s.astype('O')
        self.assertEqual(s.dtype, np.object_)

        s = Series([datetime(2001, 1, 2, 0, 0) for i in range(3)])
        s[1] = np.nan
        self.assertEqual(s.dtype, 'M8[ns]')
        s = s.astype('O')
        self.assertEqual(s.dtype, np.object_)