save project

snake.py

@@ -56,12 +56,15 @@ while True:
         y += 30
     position.append((x, y))
     if x == apple_x and y == apple_y:
+        score=score+10
         num1 = random.randint(1,22)
         num2 = random.randint(1,16)
         apple_x = 30*num1-30
         apple_y = 30*num2-30
     else:
         position.pop(0)
+    if x < 0 or x > 630 or y < 0 or y >450:
+        exit()
     # 将背景图画上去
     screen.blit(background, (0, 0))
     # 将贪吃蛇的头画上去