我想提取产品的信息，从亚马逊网站与Scrapy和 selenium 。
下面的源代码连接到亚马逊网站，然后执行搜索的字母“A”。然后我恢复搜索结果集的链接。但当我做了一个循环去到每一个搜索结果什么也没有发生（它只连接到第一个结果）。谢谢你帮助我纠正这段代码。
源代码“蜘蛛”

from scrapy.contrib.spiders import CrawlSpider
    from selenium import webdriver
    from selenium.webdriver.support.select import Select
    from time import sleep
    import selenium.webdriver.support.ui as ui
    from scrapy.xlib.pydispatch import dispatcher
    #from runner.items import RunnerItem
    from extraction.items import ProduitItem
    class RunnerSpider(CrawlSpider):
      name = 'products'
      allowed_domains = ['amazon.com']
      start_urls = ['http://www.amazon.com']

      def __init__(self):
           self.driver = webdriver.Firefox()

      def parse(self, response): 
        items = []       
        self.driver.get(response.url)
        recherche = self.driver.find_element_by_xpath('//*[@id="twotabsearchtextbox"]')
        recherche.send_keys("A")
        recherche.submit()
        #time.sleep(2.5)

        # all search results links
        resultas = self.driver.find_elements_by_xpath('//ul[@id="s-results-list-atf"]/li/div/div/div/div[2]/div[1]/a')

        for result in resultas:
          item = ProduitItem()
          lien = result
          lien.click()
          # exemple of data extracted 
          item['NOM'] = self.driver.find_element_by_xpath('//h1[@id="aiv-content-title"]').text()
          item['IMAGE'] = self.driver.find_element_by_xpath('//*[@id="dv-dp-left-content"]/div[1]/div/div/img/@src').text()
          items.append(item)

      self.driver.close()
      yield items

源代码“项目”

# -*- coding: utf-8 -*-
    import scrapy
    class ProduitItem(scrapy.Item):
       NOM = scrapy.Field()
       IMAGE = scrapy.Field()

源代码“管线”

from scrapy.exceptions import DropItem
    class DuplicatesPipeline(object):
      def __init__(self):
        self.ids_seen=set()
      def process_item(self, item, spider):
        if item['id'] in self.ids_seen:
           raise DropItem("Duplicate item found: %s"%item)
        else:
           self.ids_seen.add(item['id'])
        return item