Creating Scrapy array of items with multiple parse

Question

I am scraping listings with Scrapy. My script parses first for the listing urls using parse_node, then it parses each listing using parse_listing,

Answer 1

This is somewhat complicated issued:
You need to form a single item from multiple different urls.

Scrapy allows you to carry over data in request's meta attribute so you can do something like:

def parse_node(self,response,node):
    yield Request('LISTING LINK', callback=self.parse_listing)

def parse_listing(self,response):
    item = defaultdict(list)
    item['id'] = response.xpath('//node[@id="ListingId"]/text()').extract_first()
    item['title'] = response.xpath('//node[@id="ListingTitle"]/text()').extract_first()
    agent_urls = string.split(response.xpath('//node[@id="Agents"]/text()').extract_first() or "",'^')
    # find all agent urls and start with first one
    url = agent_urls.pop(0)
    # we want to go through agent urls one-by-one and update single item with agent data
    yield Request(url, callback=self.parse_agent, 
                  meta={'item': item, 'agent_urls' agent_urls})

def parse_agent(self,response):
    item = response.meta['item']  # retrieve item generated in previous request
    agent = dict() 
    agent['name'] = response.xpath('//node[@id="AgentName"]/text()').extract_first()
    agent['email'] =  response.xpath('//node[@id="AgentEmail"]/text()').extract_first()
    item['agents'].append(agent)
    # check if we have any more agent urls left
    agent_urls = response.meta['agent_urls']
    if not agent_urls:  # we crawled all of the agents!
        return item
    # if we do - crawl next agent and carry over our current item
    url = agent_urls.pop(0)
    yield Request(url, callback=self.parse_agent, 
                  meta={'item': item, 'agent_urls' agent_urls})