[Tutor] An OO question as relates to Python.

andy surany mongo57a@comcast.net
Mon Oct 21 23:18:11 2002


Thanks everyone! It finally clicked! I had the right code - in the wrong
place.

It is working the way I want. I appreciate the help - and the education.

Regards,

Andy
-----Original Message-----
From: Magnus Lycka <magnus@thinkware.se>
To: tutor@python.org <tutor@python.org>
Date: Monday, October 21, 2002 7:07 PM
Subject: Re: [Tutor] An OO question as relates to Python.


>At 17:29 2002-10-21 -0400, andy surany wrote:
>>I re-read the OOP section of the tutor. I guess that what I want to do is
>>inherit the attributes of the ScrolledList class to the WINMENU class. Am
I
>>anywhere near the mark?
>
>Inheritance means "is-a". An employee is a person, so it might
>be reasonable that an Emplyee class inherits from a Person class.
>WINMENU is a kind of Frame I guess, and thus inherits from Frame.
>But it IS NOT a scrolled list, is it? I think it HAS a scrolled
>list. Has implies composition, not inheritance. Your frame class
>inheriting "ScrolledList" sounds a bit like Employee inheriting
>a Salary class. An employee is definitely not a kind of salary.
>
>>But ScrolledList is not defined at the point WINMENU
>>is accessed (class WINMENU(Frame,ScrolledList) yields "ScrolledList not
>>defined"), as follows:
>
>That could be fixed by changing places, but it's not
>what you want unless I'm confused here.
>
>I think I sent a solution to this to you in a previous
>email? (Maybe you didn't see my changes in your code?)
>
>In your WINMENU class, I think you need an attribute (also
>called a member variable) that points out the ScrolledList.
>"self.myScrolledList = ScrolledList(...)" This is set when
>you create your scrolled list.
>
>When you populate the list, you simply do
>self.myScrolledList.populate_list(options)
>
>>I'm getting dizzy from going around in circles.............
>
>Well, others pay good money for such attractions
>and you get it for free! :) No hangover either,
>I hope...
>
>
>--
>Magnus Lycka, Thinkware AB
>Alvans vag 99, SE-907 50 UMEA, SWEDEN
>phone: int+46 70 582 80 65, fax: int+46 70 612 80 65
>http://www.thinkware.se/  mailto:magnus@thinkware.se
>
>
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