def __len__(self):
        if self.count is None:
            if self.objects is not None:
                self.count = len(self.objects)
            else:
                with self.backend.transaction():
                    count_select = self.get_count_select()
                    result = self.backend.connection.execute(count_select)
                    self.count = result.first()[0]
                    result.close()
        return self.count
dataset/ETHPy150Open adewes/blitzdb/blitzdb/backends/sql/queryset.py/QuerySet.__len__/original