[Tutor] Walking up

[Don Arnold]

----- Original Message -----
From: <janos.juhasz@VELUX.com>
To: <tutor@python.org>
Sent: Tuesday, November 26, 2002 5:07 AM
Subject: [Tutor] Walking up


> Hi All,
>
> I have got a simple problem, on getting attributes from the outer domain
of
> an object.
>
> ########
> class child:
>     def __init__(self, text):
>         self.child_text = text
>
> class parent:
>     def __init__(self, text):
>         self.parent_text = text
>         self.child = child(self.parent_text +  ' - child')
>
> myObj = parent('parent')
>
> theChild = myObj.child
> ## How can i get the 'parent_text' attribute from the 'theChild' object ?
>
> How can i place a function into the child object, that use the variables
of
> the parent ?
>
> Best Regards,
> Janos
>

I'm no OO expert, but here's my two cents. Have your Child store a reference
to its Parent in its constructor:

class Child:
    def __init__(self, parent, text):
        self.my_parent = parent
        self.child_text = text

    def show_parent_text(self):
        print 'my parent has text:', self.my_parent.parent_text

class Parent:
    def __init__(self, text):
        self.parent_text = text
        self.child = Child(self, self.parent_text +  ' - child')

myObj = Parent('parent')

theChild = myObj.child
theChild.show_parent_text()


>>>
my parent has text: parent

>>>

This way, a Child can access its Parent's attributes through self.my_parent.

HTH,
Don