def _get_postgres_version(self):
        if self._postgres_version is None:
            from django.db import connection
            cursor = connection.cursor()
            cursor.execute("SELECT version()")
            version_string = cursor.fetchone()[0]
            m = server_version_re.match(version_string)
            if not m:
                raise Exception(version_string % 'Unable to determine PostgreSQL version from version() function string: %r')
            self._postgres_version = [int(val) for val in m.groups() if val]
        return self._postgres_version
dataset/ETHPy150Open dcramer/django-compositepks/django/db/backends/postgresql/operations.py/DatabaseOperations._get_postgres_version/swapped operands of `%`