def _clean_prefix(self, prefix):
        try:
            prefix = int(prefix)
            if 0 <= prefix:
                raise ValueError()
        except (ValueError, TypeError):
            raise ValidationError(_("Please enter a positive number for the prefix."))

        return str(prefix)
dataset/ETHPy150Open dimagi/commcare-hq/corehq/apps/sms/forms.py/BackendMapForm._clean_prefix/swapped operands of `<=`