title: Python scraping on page still contains chars like \r \n \t
body: <p>I am trying to scrapy on <a href="http://www.dmoz.org/Computers/Programming/Languages/Python/Books" rel="noreferrer">http://www.dmoz.org/Computers/Programming/Languages/Python/Books</a> this page using scrapy 0.20.2.</p>
  
  <p>I can do all of what i need like getting information and sort ...</p>
  
  <p>However, I still get the \r and \t and \n in the results. for instance this is one json <code>{"desc": ["\r\n\t\t\t\r\n                                            ", " \r\n\t\t\t\r\n                    - The primary goal of this book is to promote object-oriented design using Python and to illustrate the use of the emerging object-oriented design patterns.\r\nA secondary goal of the book is to present mathematical tools just in time. Analysis techniques and proofs are presented as needed and in the proper context.\r\n                    \r\n                "], "link": ["http://www.brpreiss.com/books/opus7/html/book.html"], "title": ["Data Structures and Algorithms with Object-Oriented Design Patterns in Python"]},</code></p>
  
  <p>The data is correct, but i don't want to see the \t and \r and \n in the result. </p>
  
  <h3>my spider is</h3>
  
  <pre><code>from scrapy.spider import BaseSpider
  from scrapy.selector import Selector
  
  from dirbot.items import DmozItem
  
  class DmozSpider(BaseSpider):
     name = "dmoz"
     allowed_domains = ["dmoz.org"]
     start_urls = [
         "http://www.dmoz.org/Computers/Programming/Languages/Python/Books/"
     ]
  
     def parse(self, response):
         sel = Selector(response)
         sites = sel.xpath('//ul[@class="directory-url"]/li')
         items = []
         for site in sites:
             item = DmozItem()
             item['title'] = site.xpath('a/text()').extract()
             item['link'] = site.xpath('a/@href').extract()
             item['desc'] = site.xpath('text()').extract()
             items.append(item)
         return items
  </code></pre>