Use of super() with not immediate parent

Question

Is this a legal use of super()?

class A(object):
    def method(self, arg):
        pass

class B(A):
    def method(self, arg):
        super(B,self).method(arg)

class C(B):
    def method(self, arg):
        super(B,self).method(arg)

Thank you.

Looks valid to me. You might want to read this, too: http://stackoverflow.com/questions/576169/understanding-python-super — blueberryfields, May 25 '11 at 20:44

score 12 · Accepted Answer · answered May 25 '11 at 20:47

12

It will work, but it will probably confuse anyone trying to read your code (including you, unless you remember it specifically). Don't forget that if you want to call a method from a particular parent class, you can just do:

A.method(self, arg)

answered May 25 '11 at 20:47

Thomas K

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I assume, if there is no multiple-inheritance involved, both `A.method(self, arg)` and `super(B,self).method(arg)` are equivalent (minus the potential user confusion)? – upperBound May 25 '11 at 20:55
@upperBound: Yes. Although obviously in both cases you need to be aware of what happens if you change their inheritance relationships. – Thomas K May 25 '11 at 20:59

score 3 · Answer 2 · answered May 25 '11 at 20:51

3

Well, "legal" is a questionable term here. The code will end up calling A.method, since the type given to super is excluded from the search. I would consider this usage of super flaky to say the least, since it will skip a member of the inheritance hierarchy (seemingly haphhazardly), which is inconsistent with what I would expect as a developer. Since users of super are already encouraged to maintain consistency, I'd recommend against this practice.

answered May 25 '11 at 20:51

Jim Brissom

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I agree. What do you think about using `A.method(self, arg)` since this too would step over the hierarchy? – upperBound May 25 '11 at 21:08

Use of super() with not immediate parent

2 Answers2