stackoverflow_spider.py

import scrapy

class StackOverflowSpider(scrapy.Spider):
	name = 'stackoverflow'
	start_urls = ['http://stackoverflow.com/questions?sort=votes']

	def parse(self, response):

		for href in response.css('.question-summary h3 a::attr(href)'):

			full_url = response.urljoin(href.extract())
			yield scrapy.Request(full_url, callback=self.parse_question)

	def parse_question(self, response):

		yield {

			'title': response.css('h1 a::text').extract()[0],
			'votes': response.css('.question .vote-count-post::text').extract()[0],
			'body': response.css('.question .post-text').extract()[0],
			'tags': response.css('.question .post-tag::text').extract(),
			'link': response.url,
		}

From the intro to Scrapy v1.0.3.