def outlier_removal_null(dataframe, colname, low_cut, high_cut):
    """Replace outliers with empty values on dataframe[colname]"""

    col = dataframe[colname]

    dataframe.loc[
        col.apply(
            lambda x: isinstance(x, (int, float))
            and (x < low_cut or x > high_cut)
        ),
        colname,
    ] = None

    return dataframe