CODEWITHSUNDEEP
pythoninheritancemultiple-inheritance
Clawish
Clawish

Reputation: 2964

Inherit from two classes (either or)

I have the following issue with class inheritance. Given class A, B, C as follows

class A(object):
    ...

class B(A):
    ...

class C(A):
    ...

I want a class D that can either inherit from B or from C, depending on the use case. Right now, I have solved this issue by having a dynamic class definition:

def D(base_class, parameter1, parameter2):
    class D(base_class):
        ...
    return D(parameter1, parameter2)

Is this the proper way to do it, or is there a better way of solving this issue?

Upvotes: 0

Views: 600

Answers (1)

chepner
chepner

Reputation: 531798

Rather than have D both create a class and return an instance, have it just return the class, which you can then use to create multiple instances as necessary.

def make_D(base_class):
    class D(base_class):
        ...
    return D

DB = make_D(B)
DC = make_D(C)

d1 = DB(...)
d2 = DC(...)
d3 = DC(...)

At this point, you should consider whether you actually need a factory function to define your subclasses, rather than simply define DB and DC directly.

Upvotes: 1

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