CODEWITHSUNDEEP
python
Ícaro Lorran
Ícaro Lorran

Reputation: 96

How to initialize one parent at a time in multiple inheritance?

Suppose I have the following class inheriting from classes A and B:

class A:
    def __init__(self):
        self.x = 2
class B:
    def __init__(self,u):
        self.y = u + 2
class C(A,B):
    def __init__(self):
        #self.y should be 4 here

How do I initialize B only after initializing A? Using super(C,self).__init__() doesn't let me use attributes of A into B.

Upvotes: 1

Views: 64

Answers (4)

Iaggo Capitanio
Iaggo Capitanio

Reputation: 138

Just do this:

class A:
    def __init__(self):
        print("A was initialized")
        self.x = 2
    def getX(self):
        return self.x
class B:
    def __init__(self, u):
        print("B was initialized")
        self.u  = u +2
        
class C(A,B):
    def __init__(self, **kw):
        A.__init__(self)
        B.__init__(self, self.getX())

Upvotes: 1

bb1
bb1

Reputation: 7863

Alternatively, with super:

class A:
    def __init__(self):
        self.x = 2
class B:
    def __init__(self,u):
        self.y = u + 2
class C(A,B):
    def __init__(self):
        super().__init__()
        super(A, self).__init__(self.x)

Upvotes: 0

Jack Ciafardo
Jack Ciafardo

Reputation: 31

If you want to pass attributes in between classes use something like a return statement. Then in your B class use whatever the A class returned.

Upvotes: -1

Tim Roberts
Tim Roberts

Reputation: 54698

You don't HAVE to use super.

class A:
    def __init__(self):
        self.x = 2
class B:
    def __init__(self,u):
        self.y = u + 2
class C(A,B):
    def __init__(self):
        A.__init__(self)
        B.__init__(self, self.x)

Now, that does mean some pretty tight coupling, in that C has to be way too aware of what A.__init__ does.

Upvotes: 2

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