save project

diy2.py

+username = "python"
+userpassword = "123456"
+while True:
+    a = input("请输入用户名:")
+    b = input("请输入密码:")
+    if a == username and b == userpassword:
+        print("登录成功!")
+        break
+    if a!=username:
+        print("账号错误,请重新输入")
+        continue 
+    if b!=userpassword:
+        print("密码错误,请重新输入")
+
+
+print("欢迎来到贝尔编程!")