scrapy回调函数传递参数

def parse(self, response):
    for sel in response.xpath('//li[@class="clearfix"]/div[@class="list_con"]'):
        item=DmozItem()
        item['href']=sel.xpath('h2/a/@href').extract()[0]
        yield scrapy.Request(item['href'], callback=lambda response, it=item: self.others_parse(response,it),dont_filter=True)
        yield item


def others_parse(self, response, it):
    it['url'] = response.url
    yield it

def parse(self, response):
    for sel in response.xpath('//li[@class="clearfix"]/div[@class="list_con"]'):
        item=DmozItem()
        item['href']=sel.xpath('h2/a/@href').extract()[0]

        request= scrapy.Request(item['href'], callback=others_parse,dont_filter=True)
        request.meta['item'] = item
        yield request


def others_parse(self, response):
    item = response.meta['item']
    item['other_url'] = response.url
    yield item