使用Scrapy递归地为链接捕获域

Question

Here is the code I'm using for scraping all the urls of a domain:

import scrapy
from scrapy.spiders import CrawlSpider, Rule
from scrapy.linkextractors.lxmlhtml import LxmlLinkExtractor

class UrlsSpider(scrapy.Spider):
    name = 'urlsspider'
    allowed_domains = ['example.com']
    start_urls = ['http://example.com/']

    rules = (Rule(LxmlLinkExtractor(allow=(), unique=True), callback='parse', follow=True))

    def parse(self, response):
        for link in LxmlLinkExtractor(allow_domains=self.allowed_domains, unique=True).extract_links(response):
            print link.url

            yield scrapy.Request(link.url, callback=self.parse)

As you can see that I've used unique=True but it's still printing duplicate urls in the terminal whereas I want only the unique urls and not duplicate urls.

Any help on this matter will be very helpful.

Answer 1

Since the code looks at the content of the URLs recursively, you will see the duplicate URLs from the parsing of other pages. You essentially have multiple instances of LxmlLinkExtractor().