test_reshape.py 文件源码

def test_stack_ints(self):
        df = DataFrame(
            np.random.randn(30, 27),
            columns=MultiIndex.from_tuples(
                list(itertools.product(range(3), repeat=3))
            )
        )
        assert_frame_equal(
            df.stack(level=[1, 2]),
            df.stack(level=1).stack(level=1)
        )
        assert_frame_equal(
            df.stack(level=[-2, -1]),
            df.stack(level=1).stack(level=1)
        )

        df_named = df.copy()
        df_named.columns.set_names(range(3), inplace=True)
        assert_frame_equal(
            df_named.stack(level=[1, 2]),
            df_named.stack(level=1).stack(level=1)
        )