save project

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:
@@ -10,4 +12,7 @@ while True:
                 print("账号错误")
             if password != userpassword:
                 print("密码错误")
+            i=i-1
+        else:
+                exit()       
 print("欢迎来到贝尔编程!")
\ No newline at end of file