def df_swap_cols(df, columns):
    """Swaps the column by column name or index
    columns: Can be a tuple of column indexes or names
    ex. (2, -1) or ('a', 'b')
    """
    first, second = columns
    cols = list(df.columns)
    if type(first) is int:
        cols[first], cols[second] = cols[second], cols[first]
        df = df[cols]
    elif type(first) is str:
        df[first], df[second] = df[second], df[first]
    return df