sc.py 文件源码

def aggregate(cls, value):
        return {
            'average_age': func.avg(cls.age),
            'students': func.count(),
            'classes': func.count(distinct(cls.sc_class)),
            'average_class_size': func.count() / func.count(distinct(cls.sc_class)),
            'schools': func.count(distinct(cls.sc_school)),
        }[value]