[Tutor] OOD - Another class question

[Steve Willoughby]

On Sun, Feb 28, 2010 at 06:24:09PM -0500, James Reynolds wrote:
> I have another question related to OOD. What I have is a module with one
> parent class and two child classes. Some stuff is done to the object that is
> passed to the function in one of the child classes and this then calls a
> function from the global class passing local variables (from the child
> class).

I think you're confusing containers with inheritance.

> class MountainBuilder(object):
> def __init__(self, mountain):
>             self.mountain = mountain
>             self.mountain_func     <--- what's this?
>            self.pinetree_func      <--- what's this?
> 
> class HillBuilder(MountainBuilder):
> def __init__(self, mountain):
>               OptionLoad.__init__(self, mountain)
>               self.MountainBuilder.mountain_func

There is no MountainBuilder attribute in HillBuilder.  Rather,
HillBuilder is a refined type of a MountainBuilder, and inherits
everything MountainBuilders have, plus what you change or add
to that base in HillBuilder.  

You're treating it like it's a separate class which contains
a MountainBuilder object inside it as an attribute.