On Apr 5, 2:13 pm, Martin Manns <[EMAIL PROTECTED]> wrote:
> On Thu, 5 Apr 2007 16:55:38 -0400
>
>
>
> "John Clark" <[EMAIL PROTECTED]> wrote:
> > >That works, but when I replace A with something else, I do not get
> > >the
> > grandparent anymore
> > >without changing all the method calls. Basically, I would like to
> > >call the
> > method m in the first
> > >grandparent of D.
>
> > >Martin
>
> > I think the problem you may run into is with the term "first
> > grandparent" - when you look at the method resolution order of the
> > class D, you will find that the MRO goes "D, C, B, A"... I think it's
> > going to be difficult to figure out where the "first grandparent" is
> > in the MRO.
>
> > For example:
>
> > class A(object):
> > def m(self):
> > pass
> > class B(A):
> > def m(self):
> > pass
> > class C(B):
> > def m(self):
> > pass
> > class D(A):
> > def m(self):
> > pass
> > class E(C,D):
> > def m(self):
> > firstgrandparent(E,self).m() #Should call B.m
> > class F(D,C):
> > def m(self):
> > firstgrandparent(F,self).m() # Should call F.m
>
> > The mro for class E is going to be "E,C,B,D,A" where as the mro for
> > class F is going to be "F,D,C,B,A". However, the first grandparent
> > for E should be B, where as the first grandparent for F should be A.
>
> > Because the MRO isn't just a depth first traversal, the term "first
> > grandparent" gets tricky to define...
>
> Not really. The first grandparent would be the first occurrence in the
> list from left to right, which satisfies the requirement that its
> shortest path to the current class is 2.
>
> The only problem: How do I get it?
>
> Martin
class E(C,D):
def m(self):
for cls in E.__mro__:
if cls != E and cls not in E.__bases__:
cls.m(self)
break
... but it's probably better that you
rethink your class hierarchy.
--
Hope this helps,
Steven
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