save project

snake.py

@@ -58,6 +58,8 @@ while True:
         y += 30
 
     position.append((x, y))
+    if x<0 or x>630 or y<0 or y>450:
+        exit()
 
     if x==applex and y==appley:
         score+=1
@@ -69,15 +71,14 @@ while True:
         position.pop(0)
     # 将背景图画上去
     screen.blit(background, (0, 0))
+    screen.blit(food, (applex, appley))
     # 将贪吃蛇的头画上去
     screen.blit(snake_head, position[-1])
     # 将贪吃蛇的身体画上去
     for i in range(len(position)-1):
         screen.blit(body, position[i])
-
-    # 将果实画上去
-    screen.blit(food, (applex, appley))
-
+        if (x,y)==position[i]:
+            exit()
     info='Score: '+str(score)
     text=font.render(info,True,(0,0,0))
     screen.blit(text,(540,10))