Snake básico com pygame

snake.py

#!/usr/bin/python3

import pygame
from pygame.locals import *
from random import randint

def on_grid_random():
  x = randint(0, 290)
  y = randint(0, 290)
  return (x//10 * 10, y//10 * 10)

def colision(c1, c2):
  return (c1[0] == c2[0]) and (c1[1] == c2[1])

class Colors(object):
  WHITE = (255, 255, 255)
  RED =   (255, 0, 0)

class Snake(object):
  def __init__(self):
    self.body = [(200, 200), (210, 200), (220, 200)]
    self.skin = pygame.Surface((10, 10))

pygame.init()
screen = pygame.display.set_mode((300, 300))
pygame.display.set_caption('Snake')

UP = 0
RIGHT = 1
DOWN = 2
LEFT = 3

snake = Snake()
snake.skin.fill(Colors.WHITE)

apple_pos = on_grid_random()
apple = pygame.Surface((10, 10))
apple.fill(Colors.RED)

my_direction = LEFT

clock = pygame.time.Clock()

while True:
  clock.tick(15)

  for event in pygame.event.get():
    if event.type == QUIT:
      pygame.quit()

    if event.type == KEYDOWN:
      if event.key == K_UP:
        my_direction = UP
      if event.key == K_DOWN:
        my_direction = DOWN
      if event.key == K_RIGHT:
        my_direction = RIGHT
      if event.key == K_LEFT:
        my_direction = LEFT

  if colision(snake.body[0], apple_pos):
    apple_pos = on_grid_random()
    snake.body.append((0,0))

  for i in range(len(snake.body) -1, 0, -1):
    snake.body[i] = (snake.body[i-1][0], snake.body[i-1][1])

  if my_direction == UP:
    snake.body[0] = (snake.body[0][0], snake.body[0][1] - 10)
  if my_direction == DOWN:
    snake.body[0] = (snake.body[0][0], snake.body[0][1] + 10)
  if my_direction == RIGHT:
    snake.body[0] = (snake.body[0][0] + 10, snake.body[0][1])
  if my_direction == LEFT:
    snake.body[0] = (snake.body[0][0] - 10, snake.body[0][1])

  screen.fill((0,0,0))
  screen.blit(apple, apple_pos)

  for pos in snake.body:
    screen.blit(snake.skin, pos)

  pygame.display.update()