Scrapy spider crawling Stack Overflow

gistfile1.py

from scrapy.spider import  Spider
from scrapy.contrib.spiders import CrawlSpider, Rule
from scrapy.contrib.linkextractors.sgml import SgmlLinkExtractor
from scrapy.selector import Selector
from scrapy.item import Item, Field
import urllib

class Question(Item):
    tags = Field()
    answers = Field()
    votes = Field()
    date = Field()
    link = Field()

class ArgSpider(CrawlSpider):
    """
    
    Scrapes first 15 stackoverflow.com questions containing "query" within a given "tag" and 
    displays links, number of votes etc in the terminal. 

    Usage:
    
      ~: scrapy crawl StackSpider -a tag=[your tag] -a query=[your query]

    For example
        
       ~: scrapy crawl StackSpider -a tag=python -a query="crawling a website"


    """

    name = "StackSpider"

    def __init__(self,tag=None,query=None,*args,**kwargs):
        super(ArgSpider,self).__init__(*args,**kwargs)
        self.start_urls = []
        urlTemplate = "http://stackoverflow.com/search?q=%5B{tag}%5D{query}"
        query = urllib.quote(query)
        self.start_urls.append(urlTemplate.format(tag=tag,query=query))


    def parse(self,response):
        """

        @url http://stackoverflow.com/search?q=%5Bpython%5Dfiltering"
        @returns items 15
        @returns requests 0 1
        @scrapes votes answers date link

        """
        sel = Selector(response)
        elems = sel.css('.question-summary')
        results = []
        for elem in elems:
            item = Question()
            item["tags"] = elem.css('.post-tag::text').extract()
            item["votes"] = elem.css('.vote-count-post').xpath('.//strong/text()').extract()
            item["answers"] = elem.css('.status').xpath('.//strong/text()').extract()
            item["date"] = elem.css('.relativetime').xpath('.//@title').extract()
            link = elem.css('.result-link').xpath('.//a/@href').extract()
            item["link"] = link
            results.append(item)
        return results