save project

snake.py

@@ -52,10 +52,13 @@ while True:
     else:
         y += 30
     position.append((x, y))
-    position.pop(0)
     if x== ax and y ==ay:
-        ax=random.randint(0,660)
-        ay=random.randint(0,480)
+        a=random.randint(1,22)
+        b=random.randint(1,16)
+        ax=30*a-30
+        ay=30*b-30
+    else:
+        position.pop(0)
     # 将背景图画上去
     screen.blit(background, (0, 0))
     # 将贪吃蛇的头画上去