Python Attributes and Inheritance

Question

Say I have the folowing code:

class Class1(object):

    def __init__(self):
        self.my_attr = 1
        self.my_other_attr = 2

class Class2(Class1):

    def __init__(self):
        super(Class1,self).__init__()

Why does Class2 not inherit the attributes of Class1?

You may also want to check out this article: fuhm.net/super-harmful Since I read that I would just do Class1.__init__(self) — Wayne Werner
– Wayne Werner, Commented Jun 16, 2010 at 13:23
@Wayne: That article is misleading and is somewhat frowned upon (but it is a very interesting and useful read). Multiple inheritance really is the problem, super is more like part of the solution. Picking on super is like saying that seatbelts are bad because you can still get hurt in an accident. You are generally far better of if you use super. — nikow
– nikow, Commented Jun 16, 2010 at 13:27
nikow, Are there any good reads that explain why super is better? — Wayne Werner
– Wayne Werner, Commented Jun 16, 2010 at 15:02
@Wayne: artima.com/weblogs/viewpost.jsp?thread=237121 is an excellent read, and explicitly mentions the "harmful" article. In MI situations using direct calling quickly becomes incredibly hard to do right, while super remains more manageable. However, its best to avoid MI altogether if possible. — nikow
– nikow, Commented Jun 16, 2010 at 15:14

nikow · Accepted Answer · 2010-06-16 12:40:44Z

10

You used super wrong, change it to

super(Class2, self).__init__()

Basically you tell super to look above the given class, so if you give Class1 then that __init__ method is never called.

answered Jun 16, 2010 at 12:40

nikow

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detly · Accepted Answer · 2010-06-16 12:42:42Z

4

Because you're giving super the wrong class. It should be:

class Class2(Class1):

    def __init__(self):
        super(Class2,self).__init__()

answered Jun 16, 2010 at 12:42

detly

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