save project

diy.py

@@ -15,8 +15,12 @@ bros[0]="关羽"
 bros[1]="刘备"
 print("bros is:", bros)
 #[start]added by teacher
-bros_sum=bro1 + bro2 + bro3 + ['颜良'] + bros
+bros_sum=bro1 + bro2 + bro3
+print("length of initial bros_sum = ",len(bros_sum))
+bros_sum=bros_sum + ['颜良'] + bros
+print("length of bros_sum = ",len(bros_sum))
 bros_sum.extend(['吕布','赵云'])
+print("length of bros_sum after extend = ",len(bros_sum))
 print("part of bros_sum is:", bros_sum[-3:])
 print(bros_sum[13][1])
 print(bros_sum[13][-2])