[Tutor] OOP source code??

[John Duarte]

I have been enjoying the 'More OOP' thread.

Can someone point out some python source code that does a good job of 
illustrating "How it should be done"?

I have been struggling with trying to design an estimating system for a 
manufacturing process. I know that this is the perfect task for the OOP 
approach, but the path to design enlightenment is eluding me.

I don't want anybody to "do my homework for me", but the simplified examples I 
have encountered have not prepared me for tackling my problem. So, I am 
looking for some "real world" source that illustrates how OOP can be used to 
provide solutions.

Thanks,
John