Scrapy：抓取 start_urls 导致问题

Question

In my start_urls if I define the home page then scrapy doesn't crawl the page and the "if" check in parse_item function is never hit (eg : 'someurl.com/medical/patient-info'). But when I provide the same page url in start url (ie start_urls = 'someurl.com/medical/patient-info) it crawls it and hits the below check in parse_item

      from scrapy.spider import BaseSpider
      from scrapy.contrib.spiders.init import InitSpider
      from scrapy.http import Request, FormRequest
      from scrapy.selector import HtmlXPathSelector
      from tutorial.items import DmozItem
      from scrapy.contrib.spiders import CrawlSpider, Rule
      from scrapy.contrib.linkextractors.sgml import SgmlLinkExtractor
      import urlparse
      from scrapy import log

      class MySpider(CrawlSpider):

          items = []
          failed_urls = []
          duplicate_responses = []

          name = 'myspiders'
          allowed_domains = ['someurl.com']
          login_page = 'someurl.com/login_form'
          start_urls = 'someurl.com/' # Facing problem for the url here

          rules = [Rule(SgmlLinkExtractor(deny=('logged_out', 'logout',)),         follow=True, callback='parse_item')]

          def start_requests(self):

              yield Request(
                  url=self.login_page,
                  callback=self.login,
                  dont_filter=False
                  )


          def login(self, response):
              """Generate a login request."""
              return FormRequest.from_response(response,
                formnumber=1,
                formdata={'username': 'username', 'password': 'password' },
                callback=self.check_login_response)


          def check_login_response(self, response):
              """Check the response returned by a login request to see if we are
              successfully logged in.
              """
              if "Logout" in response.body:
                  self.log("Successfully logged in. Let's start crawling! :%s" % response, level=log.INFO)
                  self.log("Response Url : %s" % response.url, level=log.INFO)

                  return Request(url=self.start_urls)
              else:
                  self.log("Bad times :(", loglevel=log.INFO)


          def parse_item(self, response):


              # Scrape data from page
              hxs = HtmlXPathSelector(response)

              self.log('response came in from : %s' % (response), level=log.INFO)

              # check for some important page to crawl
              if response.url == 'someurl.com/medical/patient-info' :

                  self.log('yes I am here', level=log.INFO)

                  urls = hxs.select('//a/@href').extract()
                  urls = list(set(urls))


                  for url in urls :

                      self.log('URL extracted : %s' % url, level=log.INFO)

                      item = DmozItem()

                      if response.status == 404 or response.status == 500:
                          self.failed_urls.append(response.url)
                          self.log('failed_url : %s' % self.failed_urls, level=log.INFO)
                          item['failed_urls'] = self.failed_urls

                      else :

                          if url.startswith('http') :
                              if url.startswith('someurl.com'):
                                  item['internal_link'] = url
                                  self.log('internal_link :%s' % url, level=log.INFO)
                              else :
                                  item['external_link'] = url
                                  self.log('external_link :%s' % url, level=log.INFO)

                      self.items.append(item)

                  self.items = list(set(self.items))
                  return self.items
              else :
                  self.log('did not recieved expected response', level=log.INFO)

Answer 1

I guess start_urls has to be a list.

Try the following: start_urls = ['http://www.someurl.com/', ]