scrapy spider的几种爬取方式实例代码

本节课介绍了scrapy的爬虫框架，重点说了scrapy组件spider。

spider的几种爬取方式：

爬取1页内容 按照给定列表拼出链接爬取多页 找到‘下一页'标签进行爬取 进入链接，按照链接进行爬取

下面分别给出了示例

1.爬取1页内容

#by 寒小阳(hanxiaoyang.ml@gmail.com)import scrapyclass JulyeduSpider(scrapy.Spider):  name = "julyedu"  start_urls = [    'https://www.julyedu.com/category/index',  ]  def parse(self, response):    for julyedu_class in response.xpath('//div[@class="course_info_box"]'):      print julyedu_class.xpath('a/h4/text()').extract_first()      print julyedu_class.xpath('a/p[@class="course-info-tip"][1]/text()').extract_first()      print julyedu_class.xpath('a/p[@class="course-info-tip"][2]/text()').extract_first()      print response.urljoin(julyedu_class.xpath('a/img[1]/@src').extract_first())      print "/n"      yield {        'title':julyedu_class.xpath('a/h4/text()').extract_first(),        'desc': julyedu_class.xpath('a/p[@class="course-info-tip"][1]/text()').extract_first(),        'time': julyedu_class.xpath('a/p[@class="course-info-tip"][2]/text()').extract_first(),        'img_url': response.urljoin(julyedu_class.xpath('a/img[1]/@src').extract_first())      }

2.按照给定列表拼出链接爬取多页

#by 寒小阳(hanxiaoyang.ml@gmail.com)import scrapyclass CnBlogSpider(scrapy.Spider):  name = "cnblogs"  allowed_domains = ["cnblogs.com"]  start_urls = [    'http://www.cnblogs.com/pick/#p%s' % p for p in xrange(1, 11)    ]  def parse(self, response):    for article in response.xpath('//div[@class="post_item"]'):      print article.xpath('div[@class="post_item_body"]/h3/a/text()').extract_first().strip()      print response.urljoin(article.xpath('div[@class="post_item_body"]/h3/a/@href').extract_first()).strip()      print article.xpath('div[@class="post_item_body"]/p/text()').extract_first().strip()      print article.xpath('div[@class="post_item_body"]/div[@class="post_item_foot"]/a/text()').extract_first().strip()      print response.urljoin(article.xpath('div[@class="post_item_body"]/div/a/@href').extract_first()).strip()      print article.xpath('div[@class="post_item_body"]/div[@class="post_item_foot"]/span[@class="article_comment"]/a/text()').extract_first().strip()      print article.xpath('div[@class="post_item_body"]/div[@class="post_item_foot"]/span[@class="article_view"]/a/text()').extract_first().strip()      print ""      yield {        'title': article.xpath('div[@class="post_item_body"]/h3/a/text()').extract_first().strip(),        'link': response.urljoin(article.xpath('div[@class="post_item_body"]/h3/a/@href').extract_first()).strip(),        'summary': article.xpath('div[@class="post_item_body"]/p/text()').extract_first().strip(),        'author': article.xpath('div[@class="post_item_body"]/div[@class="post_item_foot"]/a/text()').extract_first().strip(),        'author_link': response.urljoin(article.xpath('div[@class="post_item_body"]/div/a/@href').extract_first()).strip(),        'comment': article.xpath('div[@class="post_item_body"]/div[@class="post_item_foot"]/span[@class="article_comment"]/a/text()').extract_first().strip(),        'view': article.xpath('div[@class="post_item_body"]/div[@class="post_item_foot"]/span[@class="article_view"]/a/text()').extract_first().strip(),      }