Pong.py

import tkinter as tk


class Game(tk.Frame):
    def __init__(self, master):
        super(Game, self).__init__(master)
        self.lives = 3
        self.width = 610
        self.height = 400
        self.canvas = tk.Canvas(self, bg='#aaaaff',
                                width=self.width,
                                height=self.height)
        self.canvas.pack()
        self.pack()

        self.items = {}
        self.ball = None
        self.paddle = Paddle(self.canvas, self.width/2, 326)
        self.items[self.paddle.item] = self.paddle

        for x in range(5, self.width - 5, 75):
            self.add_brick(x + 37.5, 50, 2)
            self.add_brick(x + 37.5, 70, 1)
            self.add_brick(x + 37.5, 90, 1)

        self.hud = None
        self.setup_game()
        self.canvas.focus_set()
        self.canvas.bind('<Left>',
                         lambda _: self.paddle.move(-10))
        self.canvas.bind('<Right>',
                         lambda _: self.paddle.move(10))

    def setup_game(self):
        self.add_ball()
        self.update_lives_text()
        self.text = self.draw_text(300, 200,
                                   'Press Space to start')
        self.canvas.bind('<space>',
                         lambda _: self.start_game())

    def add_ball(self):
        if self.ball is not None:
            self.ball.delete()

        paddle_coords = self.paddle.get_position()
        x = (paddle_coords[0] + paddle_coords[2]) * 0.5
        self.ball = Ball(self.canvas, x, 310)
        self.paddle.set_ball(self.ball)

    def add_brick(self, x, y, hits):
        brick = Brick(self.canvas, x, y, hits)
        self.items[brick.item] = brick

    def draw_text(self, x, y, text, size='40'):
        font = ('Helvetica', size)
        return self.canvas.create_text(x, y, text=text,
                                       font=font)

    def update_lives_text(self):
        text = 'Lives: %s' % self.lives
        if self.hud is None:
            self.hud = self.draw_text(50, 20, text, 15)
        else:
            self.canvas.itemconfig(self.hud, text=text)

    def start_game(self):
        self.canvas.unbind('<space>')
        self.canvas.delete(self.text)
        self.paddle.ball = None
        self.game_loop

    def game_loop(self):
        self.check_collisions
        num_bricks = len(self.canvas.find_withtag('brick'))
        if num_bricks == 0:
            self.ball.speed = None
            self.draw_text(300, 200, 'You win!')
        elif self.ball.get_position()[3] >= self.height:
            self.ball.speed = None
            self.lives -= 1
            if self.lives < 0:
                self.draw_text(300, 200, 'Game Over')
        else:
            self.ball.update()
            self.after(50, self.game_loop)

    def check_collisions(self):
        ball_coords = self.ball.get_position()
        items = self.canvas.find_overlapping(*ball_coords)
        objects = [self.items[x] for x in items \
                   if x in self.items]
        self.ball.collide(objects)


class GameObject(object):
    def __init__(self, canvas, item):
        self.canvas = canvas
        self.item = item

    def get_position(self):
        return self.canvas.coords(self.item)

    def move(self, x, y):
        self.canvas.move(self.item, x, y)

    def delete(self):
        self.canvas.delete(self.item)


class Ball(GameObject):
    def __init__ (self, canvas, x, y):
        self.radius=10
        self.direction=[1, -1]
        self.speed=10
        item = canvas.create_oval(x-self.radius, y-self.radius,
                                  x+self.radius, y+self.radius,
                                  fill='White')
        super(Ball, self).__init__(canvas, item)

    def update(self):
        coords = self.get_position()
        width = self.canvas.winfo_width()

        if coords[0] <= 0 or coords[2] >= width:
            self.direction[0] *- -1
        if coords[1] <= 0:
            self.direction[1] *= -1

        x = self.direction[0] * self.speed
        y = self.direction[1] * self.speed
        self.move(x, y)

    def collide(self, game_objects):
        coords = self.get_position()
        x = (coords[0] + coords[2]) * 0.5

        if len(game_objects) > 1:
            self.direction [1] *= -1

        elif len(game_objects) == 1:
            game_object = game_objects[0]
            coords = game_object.get_position()

            if x > coords[2]:
                self.direction[0] = 1

            elif x < coords[0]:
                self.direction[0] + -1

            else:
                  self.direction[1] *= -1

        for game_object in game_objects:
            if isinstance(game_object, Brick):
                game_object.hit()


class Paddle(GameObject):
    def __init__(self, canvas, x, y):
        self.width=80
        self.height=10
        self.ball=None
        item = canvas.create_rectangle(x-self.width / 2,
                                       y-self.height / 2,
                                       x+self.width /2,
                                       y+self.height / 2,
                                       fill='blue')
        super(Paddle, self).__init__(canvas, item)

    def set_ball(self, ball):
        self.ball = ball

    def move(self, offset):
        coords=self.get_position()
        width=self.canvas.winfo_width()
        if coords[0] + offset >= 0 and \
            coords[2] + offset <= width:
            super(Paddle, self).move(offset, 0)
            if self.ball is not None:
                self.ball.move(offset, 0)


class Brick(GameObject):
    COLOURS = {1: '#999999', 2: '#555555', 3: '#222222'}

    def __init__(self, canvas, x, y, hits):
        self.width=75
        self.height=20
        self.hits=hits
        colour = Brick.COLOURS[hits]
        item = canvas.create_rectangle(x-self.width / 2,
                                       y-self.height / 2,
                                       x+self.width / 2,
                                       y+self.height / 2,
                                      fill=colour,
                                      tags='brick')
        super(Brick, self).__init__(canvas, item)

    def hit(self):
        self.hits -= 1
        if self.hits==0:
            self.delete()
        else:
            self.canvas.itemconfig(self.item,
                                   fill=Brick.COLOURS[self.hits])


if __name__ == '__main__':
    root = tk.Tk()
    root.title('Hello, Pong!')
    game = Game(root)
    game.mainloop()