On Fri, 31 Oct 2014 18:57:31 -0400, Dennis Lee Bieber <wlfr...@ix.netcom.com> wrote:
>On Fri, 31 Oct 2014 14:18:44 -0400, Seymore4Head ><Seymore4Head@Hotmail.invalid> declaimed the following: > >>On Fri, 31 Oct 2014 10:43:19 -0700, Rob Gaddi >><rgaddi@technologyhighland.invalid> wrote: >> >> >>>Define a Square class, subclassed from Rectangle. Use getters/setters >>>to enforce that the length and width must be equal. Confirm that >>>length and width remain locked, and that perimeter() and area() work >>>correctly. >> >>class Rectangle: >> def __init__(self,length,width): >> self.length=length >> self.width=width >> def area(self): >> return self.length*self.width >> def perimeter(self): >> return 2*self.length+2*self.width >>class Square(Rectangle): >> def set_side (self): >> if self.length!=self.width: >> > Where's the rest of that -- not to mention you called it "set_side" but >never pass a side into it for use. > >-=-=-=-=-=-=-=- > >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) > Thanks for posting that. I had given up on trying it. I follow the changes you made up this point. I will have to think some more to get the rest of this. The way you provided a catch for not having a width, I don't understand the purpose of a Square subclass. Couldn't side just be length? BTW I am willing to forget any mention of getter/setter. We can just pretend that never happened. >class Square(Rectangle): > def __init__(self, side): > self.side = side > def _getLength(self): > return self.side > def _getWidth(self): > return self.side > def _setLength(self, vlu): > self.side = vlu > def _setWidth(self, vlu): > self.side = vlu > length = property(_getLength, _setLength) > width = property(_getWidth, _setWidth) > >aRect = Rectangle(2, 4) >print aRect.length, aRect.width, aRect.area(), aRect.perimeter() >aRect.length = 9 >print aRect.length, aRect.width, aRect.area(), aRect.perimeter() > > >aSqr = Square(3) >print aSqr.side, aSqr.length, aSqr.width, aSqr.area(), aSqr.perimeter() >aSqr.length = 4 >print aSqr.side, aSqr.length, aSqr.width, aSqr.area(), aSqr.perimeter() >aSqr.width = 5 >print aSqr.side, aSqr.length, aSqr.width, aSqr.area(), aSqr.perimeter() >aSqr.side = 7 >print aSqr.side, aSqr.length, aSqr.width, aSqr.area(), aSqr.perimeter() > >-=-=-=-=-=-=-=-=- >Microsoft Windows [Version 6.1.7601] >Copyright (c) 2009 Microsoft Corporation. All rights reserved. > >C:\Users\Wulfraed\Documents>cd "Python Progs" > >C:\Users\Wulfraed\Documents\Python Progs>property2.py >2 4 8 12 >9 4 36 26 >3 3 3 9 12 >4 4 4 16 16 >5 5 5 25 20 >7 7 7 49 28 > >C:\Users\Wulfraed\Documents\Python Progs> -- https://mail.python.org/mailman/listinfo/python-list
