Scrapy XPath all the links on the page

Question

I am trying to collect all the URLs under a domain using Scrapy. I was trying to use the CrawlSpider to start from the homepage and crawl their web. For each page, I want to use Xpath to extract all the hrefs. And store the data in a format like key-value pair.

Key: the current Url Value: all the links on this page.

class MySpider(CrawlSpider):
    name = 'abc.com'
    allowed_domains = ['abc.com']
    start_urls = ['http://www.abc.com']

    rules = (Rule(SgmlLinkExtractor()), )
    def parse_item(self, response):
        hxs = HtmlXPathSelector(response)
        item = AbcItem()
        item['key'] = response.url 
        item['value'] = hxs.select('//a/@href').extract()
        return item 

I define my AbcItem() looks like below:

from scrapy.item import Item, Field

class AbcItem(Item):

    # key: url
    # value: list of links existing in the key url
    key = Field()
    value = Field()
    pass

And when I run my code like this:

nohup scrapy crawl abc.com -o output -t csv &

The robot seems like began to crawl and I can see the nohup.out file being populated by all the configurations log but there is no information from my output file.. which is what I am trying to collect, can anyone help me with this? what might be wrong with my robot?

Answer 1

You should have defined a callback for a rule. Here's an example for getting all links from twitter.com main page (follow=False):

from scrapy.contrib.linkextractors.sgml import SgmlLinkExtractor
from scrapy.contrib.spiders import CrawlSpider, Rule
from scrapy.item import Item, Field


class MyItem(Item):
    url= Field()


class MySpider(CrawlSpider):
    name = 'twitter.com'
    allowed_domains = ['twitter.com']
    start_urls = ['http://www.twitter.com']

    rules = (Rule(SgmlLinkExtractor(), callback='parse_url', follow=False), )

    def parse_url(self, response):
        item = MyItem()
        item['url'] = response.url
        return item

Then, in the output file, I see:

http://status.twitter.com/
https://twitter.com/
http://support.twitter.com/forums/26810/entries/78525
http://support.twitter.com/articles/14226-how-to-find-your-twitter-short-code-or-long-code
...

Hope that helps.