def _calculate_iban_check_digits(self, bban: str) -> str:
        """Calculate the IBAN check digits using mod 97 algorithm."""
        raw_iban = f"{bban}{self.country_code}00"
        numeric_iban = "".join(str(ord(char) - 55) if char.isalpha() else char for char in raw_iban)
        check_digits = 98 - (int(numeric_iban) % 97)
        return str(check_digits).zfill(2)
Calculate the IBAN check digits using mod 97 algorithm.
faker/providers/bank/nl_BE/__init__.py