save project

py.py

 username="python"
 username="python"
 userpassword="123456"
 userpassword="123456"
-e1=input("账号：")
-e2=input("密码：")
-if e1 == username and e2 == userpassword:
-    print("账号密码错误！")
-else:
-    print("登陆成功!")
+while True:
+    e1=input("账号：")
+    e2=input("密码：")
+    if e1 == username and e2 == userpassword:
+        print("登录成功")
+        break
+    else:
+        print("登陆失败!")
+print("欢迎!")