def parse_song_list(self, response):
selector = Selector(response)
song_name_list = selector.xpath('//body//ul[@class="f-hide"]/li/a/text()').extract()
song_id_list = selector.xpath('//body//ul[@class="f-hide"]/li/a/@href').extract()
title = selector.xpath('//title/text()').extract()
for index, id_ in enumerate(song_id_list):
l = ItemLoader(item=PlayListItem())
l.add_value('song_name', song_name_list[index])
l.add_value('title', title)
yield scrapy.FormRequest(url=self.BASE_URL + id_, meta={'song_id': id_[9:], 'loader': l}, method='GET',
headers=self.headers, callback=self.parse_single_song)