Classic Pong game in Python - using pygame

pong.py

#PONG pygame

import random
import pygame, sys
from pygame.locals import *

pygame.init()
fps = pygame.time.Clock()

#colors
WHITE = (255,255,255)
RED = (255,0,0)
GREEN = (0,255,0)
BLACK = (0,0,0)

#globals
WIDTH = 600
HEIGHT = 400       
BALL_RADIUS = 20
PAD_WIDTH = 8
PAD_HEIGHT = 80
HALF_PAD_WIDTH = PAD_WIDTH / 2
HALF_PAD_HEIGHT = PAD_HEIGHT / 2
ball_pos = [0,0]
ball_vel = [0,0]
paddle1_vel = 0
paddle2_vel = 0
l_score = 0
r_score = 0

#canvas declaration
window = pygame.display.set_mode((WIDTH, HEIGHT), 0, 32)
pygame.display.set_caption('Hello World')

# helper function that spawns a ball, returns a position vector and a velocity vector
# if right is True, spawn to the right, else spawn to the left
def ball_init(right):
    global ball_pos, ball_vel # these are vectors stored as lists
    ball_pos = [WIDTH/2,HEIGHT/2]
    horz = random.randrange(2,4)
    vert = random.randrange(1,3)
    
    if right == False:
        horz = - horz
        
    ball_vel = [horz,-vert]

# define event handlers
def init():
    global paddle1_pos, paddle2_pos, paddle1_vel, paddle2_vel,l_score,r_score  # these are floats
    global score1, score2  # these are ints
    paddle1_pos = [HALF_PAD_WIDTH - 1,HEIGHT/2]
    paddle2_pos = [WIDTH +1 - HALF_PAD_WIDTH,HEIGHT/2]
    l_score = 0
    r_score = 0
    if random.randrange(0,2) == 0:
        ball_init(True)
    else:
        ball_init(False)


#draw function of canvas
def draw(canvas):
    global paddle1_pos, paddle2_pos, ball_pos, ball_vel, l_score, r_score
           
    canvas.fill(BLACK)
    pygame.draw.line(canvas, WHITE, [WIDTH / 2, 0],[WIDTH / 2, HEIGHT], 1)
    pygame.draw.line(canvas, WHITE, [PAD_WIDTH, 0],[PAD_WIDTH, HEIGHT], 1)
    pygame.draw.line(canvas, WHITE, [WIDTH - PAD_WIDTH, 0],[WIDTH - PAD_WIDTH, HEIGHT], 1)
    pygame.draw.circle(canvas, WHITE, [WIDTH//2, HEIGHT//2], 70, 1)

    # update paddle's vertical position, keep paddle on the screen
    if paddle1_pos[1] > HALF_PAD_HEIGHT and paddle1_pos[1] < HEIGHT - HALF_PAD_HEIGHT:
        paddle1_pos[1] += paddle1_vel
    elif paddle1_pos[1] == HALF_PAD_HEIGHT and paddle1_vel > 0:
        paddle1_pos[1] += paddle1_vel
    elif paddle1_pos[1] == HEIGHT - HALF_PAD_HEIGHT and paddle1_vel < 0:
        paddle1_pos[1] += paddle1_vel
    
    if paddle2_pos[1] > HALF_PAD_HEIGHT and paddle2_pos[1] < HEIGHT - HALF_PAD_HEIGHT:
        paddle2_pos[1] += paddle2_vel
    elif paddle2_pos[1] == HALF_PAD_HEIGHT and paddle2_vel > 0:
        paddle2_pos[1] += paddle2_vel
    elif paddle2_pos[1] == HEIGHT - HALF_PAD_HEIGHT and paddle2_vel < 0:
        paddle2_pos[1] += paddle2_vel

    #update ball
    ball_pos[0] += int(ball_vel[0])
    ball_pos[1] += int(ball_vel[1])

    #draw paddles and ball
    pygame.draw.circle(canvas, RED, ball_pos, 20, 0)
    pygame.draw.polygon(canvas, GREEN, [[paddle1_pos[0] - HALF_PAD_WIDTH, paddle1_pos[1] - HALF_PAD_HEIGHT], [paddle1_pos[0] - HALF_PAD_WIDTH, paddle1_pos[1] + HALF_PAD_HEIGHT], [paddle1_pos[0] + HALF_PAD_WIDTH, paddle1_pos[1] + HALF_PAD_HEIGHT], [paddle1_pos[0] + HALF_PAD_WIDTH, paddle1_pos[1] - HALF_PAD_HEIGHT]], 0)
    pygame.draw.polygon(canvas, GREEN, [[paddle2_pos[0] - HALF_PAD_WIDTH, paddle2_pos[1] - HALF_PAD_HEIGHT], [paddle2_pos[0] - HALF_PAD_WIDTH, paddle2_pos[1] + HALF_PAD_HEIGHT], [paddle2_pos[0] + HALF_PAD_WIDTH, paddle2_pos[1] + HALF_PAD_HEIGHT], [paddle2_pos[0] + HALF_PAD_WIDTH, paddle2_pos[1] - HALF_PAD_HEIGHT]], 0)

    #ball collision check on top and bottom walls
    if int(ball_pos[1]) <= BALL_RADIUS:
        ball_vel[1] = - ball_vel[1]
    if int(ball_pos[1]) >= HEIGHT + 1 - BALL_RADIUS:
        ball_vel[1] = -ball_vel[1]
    
    #ball collison check on gutters or paddles
    if int(ball_pos[0]) <= BALL_RADIUS + PAD_WIDTH and int(ball_pos[1]) in range(paddle1_pos[1] - HALF_PAD_HEIGHT,paddle1_pos[1] + HALF_PAD_HEIGHT,1):
        ball_vel[0] = -ball_vel[0]
        ball_vel[0] *= 1.1
        ball_vel[1] *= 1.1
    elif int(ball_pos[0]) <= BALL_RADIUS + PAD_WIDTH:
        r_score += 1
        ball_init(True)
        
    if int(ball_pos[0]) >= WIDTH + 1 - BALL_RADIUS - PAD_WIDTH and int(ball_pos[1]) in range(paddle2_pos[1] - HALF_PAD_HEIGHT,paddle2_pos[1] + HALF_PAD_HEIGHT,1):
        ball_vel[0] = -ball_vel[0]
        ball_vel[0] *= 1.1
        ball_vel[1] *= 1.1
    elif int(ball_pos[0]) >= WIDTH + 1 - BALL_RADIUS - PAD_WIDTH:
        l_score += 1
        ball_init(False)

    #update scores
    myfont1 = pygame.font.SysFont("Comic Sans MS", 20)
    label1 = myfont1.render("Score "+str(l_score), 1, (255,255,0))
    canvas.blit(label1, (50,20))

    myfont2 = pygame.font.SysFont("Comic Sans MS", 20)
    label2 = myfont2.render("Score "+str(r_score), 1, (255,255,0))
    canvas.blit(label2, (470, 20))  
    
    
#keydown handler
def keydown(event):
    global paddle1_vel, paddle2_vel
    
    if event.key == K_UP:
        paddle2_vel = -8
    elif event.key == K_DOWN:
        paddle2_vel = 8
    elif event.key == K_w:
        paddle1_vel = -8
    elif event.key == K_s:
        paddle1_vel = 8

#keyup handler
def keyup(event):
    global paddle1_vel, paddle2_vel
    
    if event.key in (K_w, K_s):
        paddle1_vel = 0
    elif event.key in (K_UP, K_DOWN):
        paddle2_vel = 0

init()


#game loop
while True:

    draw(window)

    for event in pygame.event.get():

        if event.type == KEYDOWN:
            keydown(event)
        elif event.type == KEYUP:
            keyup(event)
        elif event.type == QUIT:
            pygame.quit()
            sys.exit()
            
    pygame.display.update()
    fps.tick(60)

Its good but we might need the introduction of some machine learning so the computer does something aswell

Its good but we might need the introduction of some machine learning so the computer does something aswell

Working on it

uhh?
line 155, in
draw(window)
File "c:\Users\n\Desktop\ codes\games\pong.py", line 109, in draw
if int(ball_pos[0]) >= WIDTH + 1 - BALL_RADIUS - PAD_WIDTH and int(ball_pos[1]) in range(paddle2_pos[1] - HALF_PAD_HEIGHT,paddle2_pos[1] + HALF_PAD_HEIGHT,1):

pygame 2.0.0.dev8 (SDL 2.0.12, python 3.8.3)
Hello from the pygame community. https://www.pygame.org/contribute.html
Traceback (most recent call last):
File "/data/user/0/ru.iiec.pydroid3/files/temp_iiec_codefile.py", line 155, in
draw(window)
File "/data/user/0/ru.iiec.pydroid3/files/temp_iiec_codefile.py", line 101, in draw
if int(ball_pos[0]) <= BALL_RADIUS + PAD_WIDTH and int(ball_pos[1]) in range(paddle1_pos[1] - HALF_PAD_HEIGHT,paddle1_pos[1] + HALF_PAD_HEIGHT,1):
TypeError: 'float' object cannot be interpreted as an integer

pygame 2.1.0 (SDL 2.0.16, Python 3.10.0)
Hello from the pygame community. https://www.pygame.org/contribute.html
Traceback (most recent call last):
File "e:\python saves#PONG pygame.py", line 157, in
draw(window)
File "e:\python saves#PONG pygame.py", line 111, in draw
if int(ball_pos[0]) >= WIDTH + 1 - BALL_RADIUS - PAD_WIDTH and int(ball_pos[1]) in range(paddle2_pos[1] - HALF_PAD_HEIGHT,paddle2_pos[1]

• HALF_PAD_HEIGHT,1):
  TypeError: 'float' object cannot be interpreted as an integer
  PS E:\python saves>

What this error?
Traceback (most recent call last):
File "C:\Users\anjel\OneDrive\Área de Trabalho\progamas úteis\Pong.py", line 168, in
draw(window)
File "C:\Users\anjel\OneDrive\Área de Trabalho\progamas úteis\Pong.py", line 120, in draw
if int(ball_pos[0]) >= WIDTH + 1 - BALL_RADIUS - PAD_WIDTH and int(ball_pos[1]) in range(
TypeError: 'float' object cannot be interpreted as an integer

Nice and Simple code. Just one feedback. Please update all the lines having / to // as python 3 does not give back Integer with normal division symbol if the variables being used are not integer. hence creating a Type Error. for example:

ball_pos = [WIDTH/2,HEIGHT/2] to ball_pos = [WIDTH//2,HEIGHT//2]

Otherwise users will get TypeError: integer argument expected, got float Rest is perfect.

Worked like a charm! Or should I say PyCharm?! >:-}