save project

diy1.py

 username="python"
 username="python"
-userpassword="*****"
-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!")
+userpassword=" "
+while True:
+    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")
+    print("欢迎来到贝尔编程！")
+