基于scrapy实现的简单蜘蛛采集程序

本文实例讲述了基于scrapy实现的简单蜘蛛采集程序。分享给大家供大家参考。具体如下：

    # Standard Python library imports
    # 3rd party imports
    from scrapy.contrib.spiders import CrawlSpider, Rule
    from scrapy.contrib.linkextractors.sgml import SgmlLinkExtractor
    from scrapy.selector import HtmlXPathSelector
    # My imports
    from poetry_analysis.items import PoetryAnalysisItem
    HTML_FILE_NAME = r'.+\.html'
    class PoetryParser(object):
      """
      Provides common parsing method for poems formatted this one specific way.
      """
      date_pattern = r'(\d{2} \w{3,9} \d{4})'

      def parse_poem(self, response):
        hxs = HtmlXPathSelector(response)
        item = PoetryAnalysisItem()
        # All poetry text is in pre tags
        text = hxs.select('//pre/text()').extract()
        item['text'] = ''.join(text)
        item['url'] = response.url
        # head/title contains title - a poem by author
        title_text = hxs.select('//head/title/text()').extract()[0]
        item['title'], item['author'] = title_text.split(' - ')
        item['author'] = item['author'].replace('a poem by', '')
        for key in ['title', 'author']:
          item[key] = item[key].strip()
        item['date'] = hxs.select("//p[@class='small']/text()").re(date_pattern)
        return item
    class PoetrySpider(CrawlSpider, PoetryParser):
      name = 'example.com_poetry'
      allowed_domains = ['www.example.com']
      root_path = 'someuser/poetry/'
      start_urls = ['http://www.example.com/someuser/poetry/recent/',
             'http://www.example.com/someuser/poetry/less_recent/']
      rules = [Rule(SgmlLinkExtractor(allow=[start_urls[0] + HTML_FILE_NAME]),
                      callback='parse_poem'),
           Rule(SgmlLinkExtractor(allow=[start_urls[1] + HTML_FILE_NAME]),
                      callback='parse_poem')]

希望本文所述对大家的Python程序设计有所帮助。