save project

diy2.py

+username = "python"
+userpassword = "123456"
+while True:
+    name = input("请输入用户名:")
+    password = input("请输入密码:")
+    if name==username and password==userpassword:
+        print("登陆成功")
+        break
+    else:
+        print("用户名和密码错误!请重新输入")
+    if name!=username:
+        print("账号不存在!")
+        continue
+    if password!=userpassword:
+        print("密码错误")
+print("欢迎来到贝尔编程!")