Question

Here is a Python program.

import turtle

class Box:

    def __init__(self, x, y, width, height):

        self.x = x

        self.y = y

        self.width = width

        self.height = height

    def show(self):

        turtle.up()

        turtle.goto(x, y)

        turtle.down()

        for _ in range(2):

            turtle.forward(width)

            turtle.right(90)

            turtle.forward(height)

            turtle.right(90)

bigbox = Box(-100, -150, 200, 300)

bigbox.show()

turtle.done()

If you run the above program, it will produce an error. What is the keyword that has been missing from several places in the code inside the show() function?

Answer 1

Here in the show function you are using width and height variables which are class variables and to access class variables you have to use self with it, therefore the show function will become :

def show(self):
turtle.up()
turtle.goto(x, y)
turtle.down()
for _ in range(2):
   turtle.forward(self.width)
   turtle.right(90)
   turtle.forward(self.height)
   turtle.right(90)