save project

diy.py

+username="python"
+userpassword="142857"
+while True:
+    yourname=input("请输入您的用户账号：")
+    yourpassword=input("请输入您的用户密码：")
+    if yourname==username and yourpassword==userpassword:
+        print("登录成功")
+        break
+    if yourname!=username:
+        print("用户名不存在，请重新输入！")
+        continue
+    if yourpassword!=userpassword:
+        print("用户密码不存在，请重新输入！")
+print("欢迎来到贝尔编程！")
\ No newline at end of file