组合:

class A():    def __init__(self,x):        self.num = xclass B():    def __init__(slef,x)        self.num = xclass C():    def __init__(slef,x,y)        self.A = A(x)        self.A = B(y)    def print_jisuan(slef):        print('总共有%dA%dB'%(self.A.num,self.B.num))

python属性名和方法名不能相同!否则无法正常运行!