save project

diy2.py

 username = "python"
 username = "python"
 userpassword = "123456"
 userpassword = "123456"
 while True:
 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!")
-    print("用户名和密码错误!请重新输入")
+    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
+    if name != username:
+        print("用户名不存在，请重新输入!")
+        continue
+    if password != userpassword:
+        print("密码输入有误，请重新输入!")
 print("欢迎来到贝尔编程!")
 print("欢迎来到贝尔编程!")