代码如下。start_urls是可以爬取到信息的，可是无法匹配到其他的链接

headers={
    'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.99 Safari/537.36',
    }
    start_urls=[
        'https://chaoshi.detail.tmall.com/item.htm?id=576632421624&tbpm=3'
    ]
    rules=(
        Rule(LinkExtractor(allow=(r'https://chaoshi.detail.tmall.com/item.htm\?id=\d+&tbpm=3')),process_request='request_tagPage',callback='parse_item',follow=True),
    )
    def request_tagPage(self, request):
        newRequest = request.replace(headers=self.headers)
        return newRequest
    def parse_item(self,response):
        print(response.url)