Hi everyone,
This is my first question here. Hope to get some clarification.
Basically this question is about multiple inheritance and the usage of
super().__init__ in parent
classes.
So I have two classes that inherit from the same base class.
For example class B and class C inherit from A:
class A:
def __init__(self, arg1):
pass
class B(A):
def __init__(self, arg2):
super().__init__(arg2)
class C(A):
def __init__(self, arg1, arg2):
super().__init__(arg2)
Now I would like to create a new class D that inherits from B and C.
One note, D is the only class that I am "allowed" to change. A, B and C are
provided to me as is from an external package.
class D(B, C):
def __init__(self):
B.__init__(self, 'arg1')
C.__init__(self, 'arg1', 'arg2')
When I initialize D I get a TypeError.
TypeError: __init__() missing 1 required positional argument: 'arg2'
I get it from the invocation of super().__init__(arg2) inside the B class.
As I understand it, the super() inside B tries to call the __init__ of
class C,
because of the multiple inheritance and the MRO that is constructed.
But when B was implemented it wasn't aware of C and I assume,
B shouldn't be aware of C in any case.
It gives me the feeling that I'm trying to implement some bad practice
here, but I'm not sure why.
I would also like to hear your suggestions if there is a way to circumvent
it. Maybe by the approach described here:
https://rhettinger.wordpress.com/2011/05/26/super-considered-super/
wrapping B and C in some Adapter class.
Thanks for reading and any help.
--
https://mail.python.org/mailman/listinfo/python-list
