紧接上回，已经完成了单独的贪食蛇的控制，但是呢，居然没有苹果可以吃，所以，非常简单的加入苹果，同时呢，修改一下主程序中贪食蛇的创建，单独编写一个贪食蛇身体生成函数，这样将来要做双蛇也很简单了。
#创建一条新的蛇
def create_new_snake():
snake_body = []
snake_x = random.randint(5, rows - 5)
snake_y = random.randint(5, columns - 5)
snake_body.append([snake_x, snake_y])
snake_body.append([snake_x, snake_y + 1])
snake_body.append([snake_x, snake_y + 2])
return snake_body把主程序中所有生成新蛇的地方换成
snake = create_new_snake()
创建新苹果，苹果不能出现在蛇的身体里，所以
def create_new_apple(snake_body):
apple_in_game = False
while not apple_in_game:
apple_x = random.randint(0, rows - 1)
apple_y = random.randint(0, columns - 1)
# print(apple_x, apple_y)
if (apple_x, apple_y) not in snake_body:
new_apple = pygame.image.load('apple.png')
new_apple = pygame.transform.scale(new_apple, (tile_size - 2, tile_size - 2))
apple_x_location = apple_y * tile_size + x_margin/2
apple_y_location = apple_x * tile_size + y_margin/2
display.blit(new_apple, (apple_x_location, apple_y_location))
apple_in_game = True
return new_apple, (apple_x, apple_y), apple_x_location, apple_y_location在主程序中，主循环之前创建一个苹果
if __name__ == '__main__':
pygame.init()
snake = create_new_snake()
# 未按下按键时，默认的初识移动方向
direction = directions[random.randint(0, 3)]
# 创建一个小苹果
apple, apple_location, apple_left, apple_top = create_new_apple(snake)
# 吃到苹果标志
apple_was_eaten = False因为蛇与苹果之间有交互关系，如果蛇吃到苹果，那么蛇的身体会增加一格，也就是此次循环不删除列表的最后一个元素，所以定义了一格标志位。
在主循环中，与监测按键平级的地方，放入蛇与苹果关系检查。
if apple_location in snake:
apple, apple_location, apple_left, apple_top = create_new_apple(snake)
apple_was_eaten = True
my_score += 1无论
