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
来源：https://stackoverflow.com/questions/24805425/scrapy-crawl-only-part-of-a-website