auto save

dd.py

+a="python"
+b="123456"
+while True:
+    c=input("请输入用户名：")
+    d=input("请输入密码：")
+    if c==a and d==b:
+        print("登陆成功！")
+        break
+    if c!=a:
+        print("用户名输入错误")
+        continue
+    if d!=b:
+        print("密码输入错误")
+        continue
\ No newline at end of file

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("登录成功!")
+    print("用户名和密码错误!请重新输入")
+print("欢迎来到贝尔编程!")
\ No newline at end of file