Pong | Python Fiddle

from tkinter import *

class Table:
    #### constructor
    def __init__ (self, window, colour="black", net_colour="green",
                  width = 600, height=400,
                  vertical_net =False, horizontal_net=False) :
        self.width = width
        self.height = height
        self.colour = colour
self.canvas = Canvas(window, bg=self.colour, height=self.height, width=self.width)
self.canvas.pack()

if(vertical_net) :
    self.canvas.create_line(self.width/2, 0, self.width/2,
                            self.height, width=2, fill=net_colour, dash=(15, 23))
if (horizontal_net) :
    self.canvas.create_line(0, self.height/2, self.width,
                            self.height/2, width=2, fill=net_colour, dash=(15,23))
from tkinter import *
import table

window = Tk()
window.title("MyPong")

my_table = table.Table(window, net_colour="green", vertical_net=True
      
window.mainloop()

import table, random

class Ball:
	#### constructor
    def __init__(self, table, width=14, height=14, colour="red",
                 x_speed=6, y_speed=4, y_start=0, x_start=0) :
    	self.width = width
        self.height = height
        self.x_posn = x_start                
		self.y_posn = y_start
        self.colour = colour
        
        self.x_start = x_start
        self.y_start = y_start
        self.x_speed = x_speed
        sely.y_speed = y_speed
        self.table = table
        self.circle = self.table.draw_oval(self)

#### methods
    def start_position(self) :
    	self.x_posn = self.x_start
        self.y_posn = self.y_start
	
    def start_ball(self, x_speed, y_speed) :
    	self.x_speed = -x_speed if random.randint(0,1) else x_speed
        self.y_speed = -y_speed if random.randint(0,1) else y_speed
        
	def move_next(self) :
    	self.x_posn = self.x_posn = self.x_speed
        self.y_posn = self.y_posn = self.y_speed
        # if the ball hits the left wall:
        if(self.x_posn <= 3):
        	self.x_posn = 3
            self.x_speed = -self.x_speed	
        if(self.x_posn >= (self.table.width - (self.width - 3))) :
        	self.x_posn = 3
            self.x_speed = -self.x_speed
        if(self.y_posn <= 3) :
        	self.y_posn = 3
            self.y_speed = -self.y_speed
        if(self.y_posn

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