Final Exam Review Fall 2006: Working with classes
Post your questions here:
(a) You will see a red square (10px by 10px) with its top-leftmost pixel at the location (10,10) on a black 400px by 200px background.
(b)def setColor(self, color):
self.color = color
(c)def setSize(self, number):
self.size = number
(d)def setPosition(self, x, y):
self.position = (x, y)
(e)You will see a blue square (10px by 10px) with its top-leftmost pixel at the location (10,10) on a black 400px by 200px background.
David Poore
| Your part D would be correct, if the question said take in separate x and y coordinates. However, it asks you to take in a list or a tuple. Sweta Vajjhala |
Would this be correct?
(d) def setPosition(self, list):
self.position=(list[0], list[1])
Why the heck is self.size listed twice in addRectFilled?!
self.size is listed twice because when creating a filled rectangele you have to set the width and the height . . . the first self.size sets the width to 10, the second sets the height to 10.
I tried the second solution posted above, but the code does not change anything on the canvas. here is the code i typed in, i got the same solutions for the other methods. everything else works, but not the setPosition
>>> john = Box()
>>> john.setColor(green)
>>> john.setSize(50)
>>> john.setPosition([30, 50])
>>> john.draw(canvas)
>>> show(canvas)
>>> john.setPosition([120, 150])
>>> repaint(canvas)
>>> show(canvas)
| When you set the position, you are just updating x and y values. The canvas doesn't get updated until you draw. You need to add a call to draw before the second repaint. Colin Potts |
would (d) be
def setPosition(self, list):
self.position=list
?
the position never changed on the first one. It was still set at (10,10). Which doesn't make sense to me.
| How did you change the position and did you call that method that updated your position? - Bobby Mathew |
Ok I tried using:
class Box:
def __init__(self):
self.setDefaultColor()
self.size=10
self.position=(10,10)
def setDefaultColor(self):
self.color = red
def draw(self,canvas):
addRectFilled(canvas,self.position[0],self.position[1],self.size,self.size,self.color)
def setColor(self, color):
self.color = color
def setSize(size,number):
self.size=number
then
>>>joe = Box()
and if I try
>>>joe.setColor(blue)
or
>>>joe.setSize(20)
it returns "You are trying to access a part of the object that doesn't exist."
Whats the deal? Am I calling it wrong?
the variables for "setSize" are wrong.
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