[Tutor] Calling method in parent class

[Jeremiah Dodds]

On Tue, May 12, 2009 at 9:05 AM, The Green Tea Leaf <
thegreentealeaf at gmail.com> wrote:

> Hi,
> I've started to learn Python and I'm a bit confused over how to call a
> method in a parent class. Assume I have:
>
> class Parent(object):
>    def somemethod( self, bla ):
>        print 'Parent',bla
>
> I then create a child class that want to call somemethod. As I
> understand it I can either do it like this
>
> class Child(Parent):
>    def somemethod( self, bla ):
>        Parent.somemethod(self,bla)
>
> or like this
>
> class Child(Parent):
>    def somemethod( self, bla ):
>        super(Child,self).somemethod(bla)
>
> The first version seem to have the obvious disadvantage that I need to
> know the name of the parent class when I write the call, so I thought
> that the second version was the "proper" way of doing it. But when
> doing some research on the web it seem like the second version also
> have some problems.
>
> My question is simple: what is the "best" way of doing this and why?
> Or should I mix both these approaches?
>
> --
>

Assuming you don't have the same method in Child, just use self.somemethod:


In [2]: class Parent(object):
   ...:     def foo(self):
   ...:         print "in parent foo"
   ...:

In [3]: class Child(Parent):
   ...:     pass
   ...:

In [4]: x = Child()

In [5]: x.foo
Out[5]: <bound method Child.foo of <__main__.Child object at 0x999252c>>

In [6]: x.foo()
in parent foo

In [7]: class Child(Parent):
   ...:     def bar(self):
   ...:         self.foo()
   ...:         print "in child bar"
   ...:

In [8]: x = Child()

In [9]: x.bar()
in parent foo
in child bar
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