pong

import pygame, sys
black = (0, 0, 0); white = (255, 255, 255); red = (255, 0, 0)
pygame.init()

scr = pygame.display.set_mode((640, 480))
win = scr.get_rect()

myfont = pygame.font.Font('freesansbold.ttf', 12)
msg = myfont.render("Welcome to Pong", True, red)

msg_box = msg.get_rect()
msg_box.midtop = win.midtop

ball = pygame.Rect( 0, 0, 30, 30)
ball.center = win.center
player = pygame.Rect( 0, 0, 30, 90)
player.midleft = win.midleft

step = 5

vec = [1,0]
pygame.key.set_repeat(50,50)
fps = pygame.time.Clock()

while True:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            sys.exit()
        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_UP:
                player = player.move(0, step)

    ball = ball.move(vec)
    if ball.left < win.left or ball.right > win.right:
        vec[0] = -vec[0]
    if ball.left < player.right and \
        abs(ball.centery-player.centery) < (ball.h+player.h)/2:
        vec[0] = -vec[0]

    scr.fill(black)
    scr.blit(msg, msg_box)
    pygame.draw.rect(scr,white,ball)
    pygame.draw.rect(scr,white,player)
    pygame.display.flip()
    fps.tick(260)