auto save

diy2.py

 username = "python"
 userpassword = "123456"
+i=3
 while True:
+    if i >0:
         name = input("请输入用户名:")
         password = input("请输入密码:")
         if name == username and password == userpassword:
             print("登录成功!")
             break
-    print("用户名和密码错误!请重新输入")
+        elif name != username:
+            print("用户名错误!请重新输入") 
+            print('还有'+str(i)+'次机会')      
+        else:
+            print("密码错误!请重新输入")
+            print('还有'+str(i)+'次机会')  
+
 print("欢迎来到贝尔编程!")
\ No newline at end of file