[FIXED] Scrapy merge subsite-item with site-item

Issue

Im trying to scrape details from a subsite and merge with the details scraped with site. I've been researching through stackoverflow, as well as documentation. However, I still cant get my code to work. It seems that my function to extract additional details from the subsite does not work. If anyone could take a look I would be very grateful.

# -*- coding: utf-8 -*-
from scrapy.spiders import Spider
from scrapy.selector import Selector
from scrapeInfo.items import infoItem
import pyodbc


class scrapeInfo(Spider):
    name = "info"
    allowed_domains = ["http://www.nevermind.com"]
    start_urls = []

    def start_requests(self):

        #Get infoID and Type from database
        self.conn = pyodbc.connect('DRIVER={SQL Server};SERVER=server;DATABASE=dbname;UID=user;PWD=password')
        self.cursor = self.conn.cursor()
        self.cursor.execute("SELECT InfoID, category FROM dbo.StageItem")

        rows = self.cursor.fetchall()

        for row in rows:
            url = 'http://www.nevermind.com/info/'
            InfoID = row[0]
            category = row[1]
            yield self.make_requests_from_url(url+InfoID, InfoID, category, self.parse)

    def make_requests_from_url(self, url, InfoID, category, callback):
        request = Request(url, callback)
        request.meta['InfoID'] = InfoID
        request.meta['category'] = category
        return request

    def parse(self, response):
        hxs = Selector(response)
        infodata = hxs.xpath('div[2]/div[2]')  # input item path

        itemPool = []

        InfoID = response.meta['InfoID']
        category = response.meta['category']

        for info in infodata:
            item = infoItem()
            item_cur, item_hist = InfoItemSubSite()

            # Stem Details
            item['id'] = InfoID
            item['field'] = info.xpath('tr[1]/td[2]/p/b/text()').extract()
            item['field2'] = info.xpath('tr[2]/td[2]/p/b/text()').extract()
            item['field3'] = info.xpath('tr[3]/td[2]/p/b/text()').extract()
            item_cur['field4'] = info.xpath('tr[4]/td[2]/p/b/text()').extract()
            item_cur['field5'] = info.xpath('tr[5]/td[2]/p/b/text()').extract()
            item_cur['field6'] = info.xpath('tr[6]/td[2]/p/b/@href').extract()

            # Extract additional information about item_cur from refering site
            # This part does not work
            if item_cur['field6'] = info.xpath('tr[6]/td[2]/p/b/@href').extract():
                url = 'http://www.nevermind.com/info/sub/' + item_cur['field6'] = info.xpath('tr[6]/td[2]/p/b/@href').extract()[0]
                request = Request(url, housingtype, self.parse_item_sub)
                request.meta['category'] = category
                yield self.parse_item_sub(url, category)
            item_his['field5'] = info.xpath('tr[5]/td[2]/p/b/text()').extract()
            item_his['field6'] = info.xpath('tr[6]/td[2]/p/b/text()').extract()
            item_his['field7'] = info.xpath('tr[7]/td[2]/p/b/@href').extract()      

            item['subsite_dic'] = [dict(item_cur), dict(item_his)]

            itemPool.append(item)
            yield item
        pass

        # Function to extract additional info from the subsite, and return it to the original item.
        def parse_item_sub(self, response, category):
            hxs = Selector(response)
            subsite = hxs.xpath('div/div[2]')  # input base path

            category = response.meta['category']

            for i in subsite:        
                item = InfoItemSubSite()    
                if (category == 'first'):
                    item['subsite_field1'] = i.xpath('/td[2]/span/@title').extract()            
                    item['subsite_field2'] = i.xpath('/tr[4]/td[2]/text()').extract()
                    item['subsite_field3'] = i.xpath('/div[5]/a[1]/@href').extract()
                else:
                    item['subsite_field1'] = i.xpath('/tr[10]/td[3]/span/@title').extract()            
                    item['subsite_field2'] = i.xpath('/tr[4]/td[1]/text()').extract()
                    item['subsite_field3'] = i.xpath('/div[7]/a[1]/@href').extract()
                return item
            pass

I've been looking at these examples together with a lot of other examples (stackoverflow is great for that!), as well as scrapy documentation, but still unable to understand how I get details send from one function and merged with the scraped items from the original function.

how do i merge results from target page to current page in scrapy? How can i use multiple requests and pass items in between them in scrapy python

Solution

What you are looking here is called request chaining. Your problem is - yield one item from several requests. A solution to this is to chain requests while carrying your item in requests meta attribute.
Example:

def parse(self, response):
    item = MyItem()
    item['name'] = response.xpath("//div[@id='name']/text()").extract()
    more_page = # some page that offers more details
    # go to more page and take your item with you.
    yield Request(more_page, 
                  self.parse_more,
                  meta={'item':item})  


def parse_more(self, response):
    # get your item from the meta
    item = response.meta['item']
    # fill it in with more data and yield!
    item['last_name'] = response.xpath("//div[@id='lastname']/text()").extract()
    yield item 

Answered By - Granitosaurus