History     January      A
                    Geography   February     B
        Coursework  History     March        A
                    Geography   April        C
        dtype: object

        In the following example, we will swap the levels of the indices.
        Here, we will swap the levels column-wise, but levels can be swapped row-wise
        in a similar manner. Note that column-wise is the default behaviour.
        By not supplying any arguments for i and j, we swap the last and second to
        last indices.

        >>> s.swaplevel()
        Final exam  January     History         A
                    February    Geography       B
        Coursework  March       History         A
                    April       Geography       C
        dtype: object

        By supplying one argument, we can choose which index to swap the last
        index with. We can for example swap the first index with the last one as
        follows.

        >>> s.swaplevel(0)
        January     History     Final exam      A
        February    Geography   Final exam      B
        March       History     Coursework      A
        April       Geography   Coursework      C
        dtype: object

        We can also define explicitly which indices we want to swap by supplying values
        for both i and j. Here, we for example swap the first and second indices.

        >>> s.swaplevel(0, 1)
        History     Final exam  January         A
        Geography   Final exam  February        B
        History     Coursework  March           A
        Geography   Coursework  April           C
        dtype: object)