Classes

Seymore4Head Seymore4Head at Hotmail.invalid
Sat Nov 1 17:42:10 CET 2014


On Sat, 01 Nov 2014 12:00:46 -0400, Dennis Lee Bieber
<wlfraed at ix.netcom.com> wrote:

>On Fri, 31 Oct 2014 19:32:13 -0400, Seymore4Head
><Seymore4Head at Hotmail.invalid> declaimed the following:
>
>>
>>class Rectangle(object):
>>    def __init__(self, length, width=None):
>>        self.length = length
>>        if width is None:
>>            self.width = length
>>        else:
>>            self.width = width
>>    def area(self):
>>        return self.length * self.width
>>    def perimeter(self):
>>        return 2 * (self.length + self.width)
>>
>>class Square(Rectangle):
>>    def area(self):
>>        return self.length * self.width
>>    def perimeter(self):
>>        return 2 * (self.length + self.width)    
>>
>	Why did you redefine area and perimeter? Those are supposed to be
>inherited operations from Rectangle. You've duplicated what should not have
>been changed, and removed everything that makes a Square a Square.
>
>	The "assignment" was to create a Square class that enforces the
>property of "squareness" (length = width, or a simple "side").
>
>	What you created does not do that.
>    
>>a=Rectangle(3,5)
>>print (a.area())
>>print (a.perimeter())
>>b=Rectangle(5,7)
>>print (b.area())
>>print (b.perimeter())
>>c=Square(4)
>>print (c.area())
>>print (c.perimeter())
>
>	You're tests ignore the case of /changing/ side/length/width...
>Consider what happens if you execute
>
>c.length = 5
>c.width = 9
>
OK  Maybe I misunderstood the question.

My answer to you then is ......I don't know.  I will have to think
about it some more.



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