Question

以下是我的情况，我应该写什么来代替评论？

提前谢谢你，如果我问了一些问题，我很抱歉。

我已经找到答案，但没有成功。

#!/usr/bin/python3.4
class A(object):
    def __init__(self):
        print("A constructor")

class B(A):
    def __init__(self):
        super(B, self).__init__()
        print("B constructor")

class C(A):
    def __init__(self):
        super(C, self).__init__()
        print("C constructor")

class D(B,C):
    def __init__(self):
        """ what to put here in order to get printed:
            B constructor
            C constructor
            A constructor
            D constructor
                  or                
            C constructor
            B constructor
            A constructor
            D constructor
                   ?
            (notice I would like to print once 'A constructor')
        """
        print("D constructor")

if __name__ == "__main__":
    d = D()

Answer 1

我发现改变一点类构造函数代码可以满足我的需求：

#!/usr/bin/python3.4
class A(object):
    def __init__(self):
        print("A constructor")

class B(A):
    def __init__(self):
        if self.__class__ == B:
            A.__init__(self)
        print("B constructor")

class C(A):
    def __init__(self):
        if self.__class__ == C:
            A.__init__(self)
        print("C constructor")

class D(B,C):
    def __init__(self):
        B.__init__(self)        #
        C.__init__(self)        # if B constructor should be
        A.__init__(self)        # called before of C constructor
        print("D constructor")  #

#        C.__init__(self)       #
#        B.__init__(self)       # if C constructor should be
#        A.__init__(self)       # called before of B constructor
#        print("D constructor") #

if __name__ == "__main__":
    d = D()

Python3.4多继承调用特定的构造函数

1 个答案: