小编Dan*_*Vim的帖子

import scrapy
from tutorial.items import DmozItem

class DmozSpider(scrapy.Spider):
    name = "dmoz"
    allowed_domains = ["dmoz.org"]
    start_urls = [
        "http://www.dmoz.org/Computers/Programming/Languages/Python/Books/",
        "http://www.dmoz.org/Computers/Programming/Languages/Python/Resources/"
    ]

    def parse(self, response):
        for sel in response.xpath('//ul/li'):
            item = DmozItem()
            item['title'] = sel.xpath('a/text()').extract()
            item['link'] = sel.xpath('a/@href').extract()
            item['desc'] = sel.xpath('text()').extract()
            yield item

最近在学习Scrapy。当我测试教程时。我只是从文档中复制代码，但效果不佳，显示错误：

Traceback (most recent call last):
File "C:\Python27\lib\site-packages\scrapy\utils\defer.py", line 102, in iter_errback
yield next(it)
File "C:\Python27\lib\site-packages\scrapy\spidermiddlewares\offsite.py", line 28, in process_spider_output
for x in result:
File "C:\Python27\lib\site-packages\scrapy\spidermiddlewares\referer.py", line 22, in <genexpr>
return (_set_referer(r) for r in result or ())
File …