abstract_models.py 文件源码

def get_weight_variance(self, *args, **kwargs):
        Weight = apps.get_model('ddm_core', 'Weight')

        weights = Weight.objects.filter(criterion=self, *args, **kwargs).values_list('value', flat=True)
        try:
            return statistics.variance(weights)
        except statistics.StatisticsError:
            return 0