python类的初始化方法和类的init方法：

class Rectangle:
    def __init__(self,length,weight):#初始化方法
        self.length = length
        self.weight=weight
    def area(self):
        return self.length * self.weight
    def __repr__(self):
        return str(self.length*self.weight)

class square(Rectangle):
    def __call__(self):#call方法实现类的名称可调用
       print((self.length+self.weight)*2)#调用时打印边长

sq = square(20,33)
print(sq)
sq()#类的实例可调用


结果：
660
106