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
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#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
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#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(), } |
3.找到‘下一页'标签进行爬取
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import scrapyclass QuotesSpider(scrapy.Spider): name = "quotes" start_urls = [ 'http://quotes.toscrape.com/tag/humor/', ] def parse(self, response): for quote in response.xpath('//div[@class="quote"]'): yield { 'text': quote.xpath('span[@class="text"]/text()').extract_first(), 'author': quote.xpath('span/small[@class="author"]/text()').extract_first(), } next_page = response.xpath('//li[@class="next"]/@herf').extract_first() if next_page is not None: next_page = response.urljoin(next_page) yield scrapy.Request(next_page, callback=self.parse) |
4.进入链接，按照链接进行爬取
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#by 寒小阳(hanxiaoyang.ml@gmail.com)import scrapyclass QQNewsSpider(scrapy.Spider): name = 'qqnews' start_urls = ['http://news.qq.com/society_index.shtml'] def parse(self, response): for href in response.xpath('//*[@id="news"]/div/div/div/div/em/a/@href'): full_url = response.urljoin(href.extract()) yield scrapy.Request(full_url, callback=self.parse_question) def parse_question(self, response): print response.xpath('//div[@class="qq_article"]/div/h1/text()').extract_first() print response.xpath('//span[@class="a_time"]/text()').extract_first() print response.xpath('//span[@class="a_catalog"]/a/text()').extract_first() print "\n".join(response.xpath('//div[@id="Cnt-Main-Article-QQ"]/p[@class="text"]/text()').extract()) print "" yield { 'title': response.xpath('//div[@class="qq_article"]/div/h1/text()').extract_first(), 'content': "\n".join(response.xpath('//div[@id="Cnt-Main-Article-QQ"]/p[@class="text"]/text()').extract()), 'time': response.xpath('//span[@class="a_time"]/text()').extract_first(), 'cate': response.xpath('//span[@class="a_catalog"]/a/text()').extract_first(), } |
总结
以上就是本文关于scrapy spider的几种爬取方式实例代码的全部内容，希望对大家有所帮助。感兴趣的朋友可以继续参阅本站其他相关专题，如有不足之处，欢迎留言指出。感谢朋友们对本站的支持！
原文链接：http://blog.csdn.net/nnnnnnnnnnnny/article/details/54342423
