title: Scrapy JSON export issues
body: <p>I have been following some tutorials online to use Scrapy to scrape Craigslist for emails. I have this code but when I run the command and export to json file, it creates the file but the only thing in there is a single '['.</p>
  <p>Any help would be greatly appreciated. Below is my code:</p>
  <pre><code>from scrapy.spider import BaseSpider 
  from scrapy.selector import HtmlXPathSelector 
  from scrapy_demo.items import ScrapyDemoItem
  import urlparse 
  from scrapy.http.request import Request
  
  class ScrapyDemoSpider(BaseSpider): 
      name = &quot;scrapy_demo&quot;
      allowed_domains = [&quot;buffalo.craigslist.org&quot;]
      start_urls = ['http://buffalo.craigslist.org/search/cps/']
  
      def parse(self, response):
          hxs = HtmlXPathSelector(response) 
          listings = hxs.select('//....') 
          links = []
  
          #scrape listings page to get listing links
          for listing in listings:
              link = listing.select('..../@href').extract()[0]
              links.append(link)
  
          #parse listing url to get content of the listing page
          for link in links:
              item = ScrapyDemoItem()
              item['link'] = link
              yield Request(urlparse.urljoin(response.url, link), meta={'item': item}, callback=self.parse_listing_page)
  
              #get next button link
              next_page = hxs.select(&quot;//..../@href&quot;).extract()[0]
              if next_page:
                  yield Request(urlparse.urljoin(response.url, next_page), self.parse)
  
      #scrape listing page to get content
      def parse_listing_page(self, response):
          hxs = HtmlXPathSelector(response)
          item = response.request.meta['item']
          item['title'] = hxs.select('//..../text()').extract()[0]
          item['content'] = hxs.select('//..../text()').extract()[0]
          yield item
  </code></pre>