Scrapy crawl only part of a website

问题:

Hello there I have the following code to scan all links in a give site.

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


class SampleItem(Item):
    link = Field()


class SampleSpider(CrawlSpider):
    name = "sample_spider"
    allowed_domains = ["domain.com"]
    start_urls = ["http://domain.com"]

    rules = (
        Rule(LinkExtractor(), callback='parse_page', follow=True),
    )

    def parse_page(self, response):
        item = SampleItem()
        item['link'] = response.url
        return item

If I'like to check only part of a global site how could I do it? I have tried for example to scan only the french part of an international site whose domain is structured as : domain.com/fr/fr. So I have tried doing :

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


class SampleItem(Item):
    link = Field()


class SampleSpider(CrawlSpider):
    name = "sample_spider"
    allowed_domains = ["domain.com/fr/fr"]
    start_urls = ["http://domain.com/fr/fr"]

    rules = (
        Rule(LinkExtractor(), callback='parse_page', follow=True),
    )

    def parse_page(self, response):
        item = SampleItem()
        item['link'] = response.url
        return item

But the spider only returns 3 results instead of thousands. What am I doing wrong?

回答1:

To crawl only part of a website, you have to use the LinkExtractor. You can get a sample by issueing scrapy genspider -t crawl domain domain.com.

# -*- coding: utf-8 -*-
import scrapy
from scrapy.contrib.linkextractors import LinkExtractor
from scrapy.contrib.spiders import CrawlSpider, Rule

from test.items import testItem


class DomainSpider(CrawlSpider):
    name = 'domain'
    allowed_domains = ['domain.com']
    start_urls = ['http://www.domain.com/fr/fr']

    rules = (
        Rule(LinkExtractor(allow=r'fr/'), callback='parse_item', follow=True),
    )

    def parse_item(self, response):
        i = testItem()
        #i['domain_id'] = response.xpath('//input[@id="sid"]/@value').extract()
        #i['name'] = response.xpath('//div[@id="name"]').extract()
        #i['description'] = response.xpath('//div[@id="description"]').extract()
        return i