Check the given dataframe for the required columns

def check_dataframe(self, dataframe):
        """Check the given dataframe for the required columns
        """
        required_columns = (
            'a',
            'b',
            'm',
            'n',
            'r',
        )
        for column in required_columns:
            if column not in dataframe:
                raise Exception('Required column not in dataframe: {0}'.format(
                    column
                ))