ract_national_insurance(
        ...     subtract_state_tax(subtract_federal_tax(df), rate=0.12),
        ...     rate=0.05,
        ...     rate_increase=0.02)  # doctest: +SKIP

        You can write

        >>> (
        ...     df.pipe(subtract_federal_tax)
        ...     .pipe(subtract_state_tax, rate=0.12)
        ...     .pipe(subtract_national_insurance, rate=0.05, rate_increase=0.02)
        ... )
            Salary   Others
        0  5892.48   736.56
        1  6997.32      NaN
        2  3682.80  1473.12

        If you have a function that takes the data as (say) the second
        argument, pass a tuple indicating which keyword expects the
        data. For example, suppose ``national_insurance`` takes its data as ``df``
        in the second argument:

        >>> def subtract_national_insurance(rate, df, rate_increase):
        ...     new_rate = rate + rate_increase
        ...     return df * (1 - new_rate)
        >>> (
        ...     df.pipe(subtract_federal_tax)
        ...     .pipe(subtract_state_tax, rate=0.12)
        ...     .pipe(
        ...         (subtract_national_insurance, 'df'),
        ...         rate=0.05,
        ...         rate_increase=0.02
        ...     )
        ... )
            Salary   Others
        0  5892.48   736.56
        1  6997.32      NaN
        2  3682.80  1473.12
        Nrä