请教一下有关scrapy中crawlspider跟进网页的问题

这段时间在学习scrapy来作爬虫完，粗粗看完里tutorials之后就拿小米的招聘网站练手，一开始用最简单的scrapy.spider爬第一页多时候很简单，但是在改成crawlspider爬完所有的招聘信息的时候就不知道为什么进行不下去了，不仅不跟进，第一个网页也不爬了，一开始怀疑是rules除了问题，但是用shell测试过可以得到后续多链接，所以我很疑惑，希望能有大神指教。

spider部分的代码如下

import scrapy

from scrapy.spiders import CrawlSpider, Rule

from scrapy.linkextractors import LinkExtractor

from xiaomihr.items import XiaomihrItem



class XiaomihrSpider(CrawlSpider):

    name = "xiaomihr"

    allowed_domains = ["http://hr.xiaomi.com"]

    start_urls = ["http://hr.xiaomi.com/job/list"]



    rules = [

        Rule(LinkExtractor(allow = ('/job/list/.*',),restrict_xpaths=('//a[@number="numbers last"]')), callback='parse_item') #提取下一页中的链接，跟进到下一页

    ]



    def parse_item(self, response):

        self.logger.info('Now is spidering in this page:   %s', response.url)

        base = response.xpath('//div[@class="bd bd-table-list"]//tr')

        for sel in base:

            item = XiaomihrItem()

            item['work'] = sel.xpath('td[1]/a/text()').extract()

            item['worktype'] = sel.xpath('td[2]/text()').extract()

            item['location'] = sel.xpath('td[3]/text()').extract()

            item['detail_link'] = sel.xpath('td[1]/a/@href').extract()

         return item

        

然后运行之后的部分信息

2015-07-31 23:16:32 [scrapy] INFO: Scrapy 1.0.1 started (bot: xiaomihr)
2015-07-31 23:16:32 [scrapy] INFO: Optional features available: ssl, http11
2015-07-31 23:16:32 [scrapy] INFO: Overridden settings: {'NEWSPIDER_MODULE': 'xiaomihr.spiders', 'FEED_FORMAT': 'csv', 'SPIDER_MODULES': ['xiaomihr.spiders'], 'FEED_URI': 'items.csv', 'BOT_NAME': 'xiaomihr'}
2015-07-31 23:16:32 [py.warnings] WARNING: :0: UserWarning: You do not have a working installation of the service_identity module: 'No module named service_identity'. Please install it from <https://pypi.python.org/pypi/service_identity> and make sure all of its dependencies are satisfied. Without the service_identity module and a recent enough pyOpenSSL to support it, Twisted can perform only rudimentary TLS client hostname verification. Many valid certificate/hostname mappings may be rejected.

2015-07-31 23:16:32 [scrapy] INFO: Enabled extensions: CloseSpider, FeedExporter, TelnetConsole, LogStats, CoreStats, SpiderState
2015-07-31 23:16:32 [scrapy] INFO: Enabled downloader middlewares: HttpAuthMiddleware, DownloadTimeoutMiddleware, UserAgentMiddleware, RetryMiddleware, DefaultHeadersMiddleware, MetaRefreshMiddleware, HttpCompressionMiddleware, RedirectMiddleware, CookiesMiddleware, ChunkedTransferMiddleware, DownloaderStats
2015-07-31 23:16:32 [scrapy] INFO: Enabled spider middlewares: HttpErrorMiddleware, OffsiteMiddleware, RefererMiddleware, UrlLengthMiddleware, DepthMiddleware
2015-07-31 23:16:32 [scrapy] INFO: Enabled item pipelines:
2015-07-31 23:16:32 [scrapy] INFO: Spider opened
2015-07-31 23:16:32 [scrapy] INFO: Crawled 0 pages (at 0 pages/min), scraped 0 items (at 0 items/min)
2015-07-31 23:16:32 [scrapy] DEBUG: Telnet console listening on 127.0.0.1:6023
2015-07-31 23:16:32 [scrapy] DEBUG: Crawled (200) <GET http://hr.xiaomi.com/job/list> (referer: None)
2015-07-31 23:16:32 [scrapy] INFO: Closing spider (finished)