def test_pad_nan(self): x = TimeSeries([np.nan, 1., np.nan, 3., np.nan], ['z', 'a', 'b', 'c', 'd'], dtype=float) x = x.fillna(method='pad') expected = TimeSeries([np.nan, 1.0, 1.0, 3.0, 3.0], ['z', 'a', 'b', 'c', 'd'], dtype=float) assert_series_equal(x[1:], expected[1:]) self.assert_(np.isnan(x[0]), np.isnan(expected[0]))