e_axis("limbs", axis="columns")
        >>> df
        limbs   num_legs  num_arms
        animal
        dog            4         0
        cat            4         0
        monkey         2         2

        **MultiIndex**

        >>> df.index = pd.MultiIndex.from_product([['mammal'],
        ...                                        ['dog', 'cat', 'monkey']],
        ...                                       names=['type', 'name'])
        >>> df
        limbs          num_legs  num_arms
        type   name
        mammal dog            4         0
               cat            4         0
               monkey         2         2

        >>> df.rename_axis(index={'type': 'class'})
        limbs          num_legs  num_arms
        class  name
        mammal dog            4         0
               cat            4         0
               monkey         2         2

        >>> df.rename_axis(columns=str.upper)
        LIMBS          num_legs  num_arms
        type   name
        mammal dog            4         0
               cat            4         0
               monkey         2         2
        ©