How to use the finviz.helper_functions.display_functions.create_table_string function in finviz

def __str__(self):
        """ Returns a readable representation of a table. """

        table_list = [PORTFOLIO_HEADERS]

        for row in self.data:
            table_list.append([row[col] or '' for col in PORTFOLIO_HEADERS])

        return create_table_string(table_list)

def __str__(self):
        """ Returns a readable representation of a table. """

        table_list = [self.headers]

        for row in self.data:
            table_list.append([row[col] or '' for col in self.headers])

        return create_table_string(table_list)