save project

diy2.py

+un = "python"
+up = "123456"
+while True:
+    nm = input("请输入用户名:")
+    pw = input("请输入密码:")
+    if nm == un and pw == up:
+        print("登录成功!")
+        break
+    if nm != un:
+        print("用户名错误")
+    if pw != up:
+        print("密码错误")
+print("欢迎来到贝尔编程!")