On Sun, Sep 19, 2010 at 7:02 PM, Roelof Wobben <rwob...@hotmail.com> wrote: > > > > ---------------------------------------- >> From: rwob...@hotmail.com >> To: __pete...@web.de >> Subject: RE: [Tutor] Can this be done easly >> Date: Sun, 19 Sep 2010 17:01:22 +0000 >> >> >> >> >> ---------------------------------------- >>> To: tutor@python.org >>> From: __pete...@web.de >>> Date: Sun, 19 Sep 2010 18:27:54 +0200 >>> Subject: Re: [Tutor] Can this be done easly >>> >>> Roelof Wobben wrote: >>> >>>>> Hint: why does this work: >>>>> >>>>>> def __init__(self, x=0, y=0): >>>>> >>>>> ...while this doesnt: >>>>> >>>>>> def _init_(self, base_point, width=0, length=0): >>>>> >>>>> Peter >>> >>>> Maybe because base_point has no value ? >>> >>> No. One __init__ has two underscores (correct) on each side, the other >>> _init_ only one (wrong). >>> >>> _______________________________________________ >>> Tutor maillist - Tutor@python.org >>> To unsubscribe or change subscription options: >>> http://mail.python.org/mailman/listinfo/tutor >> >> > > Hello, > > Everybody thanks. > > For this exercise : > > 3.Write a function named move_rect that takes a Rectangle and two parameters > named dx and dy. It should change the location of the rectangle by adding dx > to the x coordinate of corner and adding dy to the y coordinate of corner. > > Is this one of the possible solutions : > > > class Point: > def __init__(self, x=0, y=0): > self.x = x > self.y = y > > class Rectangle(object): > def __init__(self, base_point, width=0, length=0): > self.base_point = base_point > self.width = width > self.length = length > > def moverect(rectangle, dx, dy): > rechthoek.base_point.y += dy > rechthoek.base_point.x +=dx > return rechthoek > > punt = Point(3,4) > rechthoek = Rectangle (punt,20,30) > test = moverect (Rectangle, 4,3) > print rechthoek.base_point.x
This test happens to work, but your program is incorrect. In moverect, you should work with the local variable (rectangle), not with the global one (rechthoek), because it should be possible to call it for any Rectangle, not just with the Rectangle that happens to be called rechthoek. Then, when you call it, you should specify the Rectangle that you call it for, so test = moverect (Rectangle, 4, 3) should be test = moverect(rechthoek, 4, 3) Furthermore, you do not use test (which will be null anyway), so you can shorten this to moverect(rechthoek, 4, 3) -- André Engels, andreeng...@gmail.com _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
