Newby Q: nested classes, access of upper method
Nick Coghlan
ncoghlan at email.com
Sat Dec 4 03:59:53 EST 2004
Gregor Horvath wrote:
> Hello,
>
> class A(self):
> def A1():
> pass
>
> class B(self):
> def B1():
> #************************************
> #*** How can I access A1 here???? ***
> #************************************
> self.A1() # doesnet work because self references to B
> self.self.A1() #doesnt work either
>
>
> Renanimg class B(self1): doesnt work either because self is not bound.
OK, I suspect you're a little confused about how classes work. The items in
brackets after a class name are the *base* classes of a class, not the way the
class refers to itself. So Python will complain if the listed items can't be
inherited from for one reason or another.
I suggest having another read of the tutorial section on classes to figure out
exactly what you want to be doing:
http://www.python.org/doc/2.3.4/tut/node11.html
> How can I access a method of a "upper" class?
Merely defining one class inside another class does not automatically give
instances of that inner class a reference to an instance of the outer class - if
such a reference is needed, it must be provided in the inner class's constructor.
E.g.
class A(object):
class B(object):
def __init__(self, owner):
self._owner = owner
def B1(self):
self._owner.A1()
def A1(self):
pass
def makeB(self):
return A.B(self)
Cheers,
Nick.
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