scrapy基础知识之 CrawlSpiders(爬取腾讯校内招聘):

import scrapy
from scrapy.spider import CrawlSpider,Rule
from scrapy.linkextractors import LinkExtractor
from tencent.items import TencentItem

class TencentSpider(CrawlSpider):
    name = "Tencent"
    allowed_domains = ["tencent.com"]
    # url="http://hr.tencent.com/position.php?&start="
    # offset=0
    start_urls = [ "http://hr.tencent.com/position.php?&start=0#a"]

    page_link=LinkExtractor(allow=("start=d+"))

    rules=[
            Rule(page_link,callback = "parseContent",follow=True)
    ]

    def parseContent(self, response):
        list=response.xpath('//tr[@class="even"] | //tr[@class="odd"]')
        for infos in list:
            item=TencentItem()
            item['positionname']=infos.xpath("./td[1]/a/text()").extract()[0]
            item['positionlink']=infos.xpath("./td[1]/a/@href").extract()[0]
            item['positionType']=infos.xpath("./td[2]/text()").extract()
            item['positionNum']=infos.xpath("./td[3]/text()").extract()[0]
            item['positionLocation']=infos.xpath("./td[4]/text()").extract()[0]
            item['publishTime']=infos.xpath("./td[5]/text()").extract()[0]

            yield item


运行： scrapy crawl Tencent
#注意：千万记住callback不能写 parse，由于CrawlSpider使用parse方法来实现其逻辑，如果覆盖了 parse方法，crawl spider将会运行失败