save project

diy2.py

@@ -6,10 +6,9 @@ while True:
     if a == username and b == userpassword:
         print("登录成功!")
         break
-    if a!=username:
+    elif a!=username:
         print("账号错误,请重新输入")
-        continue 
-    if b!=userpassword:
+    else:
         print("密码错误,请重新输入")