auto save

diy1.py

@@ -4,7 +4,7 @@ t1=time.time()
 print('begin at the time of',t1)
 for a in range(0, 1000):
     for b in range(0, 1000):
-        list1.insert(0, 0)
+        list1.append(0)
 t2=time.time()
 print('end at the time of ',t2)
 t3=t2-t1