怎么解决scrapy的request.url的编码问题？

Question

原始URL：http://baijiahao.baidu.com/s?id=1587742763413645693

浏览器重定向为：https://sv.baidu.com/videoui/page/videoland?pd=bjh&context={%22nid%22:%22sv_3366355432183616681%22,%22sourceFrom%22:%22bjh%22}&fr=bjhauthor&type=video

scrapy框架重定向为：https://sv.baidu.com/videoui/page/videoland?pd=bjh&context=%7B%22nid%22:%22sv_13089495717147978499%22,%22sourceFrom%22:%22bjh%22%7D&fr=bjhauthor&type=video

导致请求错误返回404，求大神指点啊！！！