Question

我试图从子网站抓取详细信息并与使用网站抓取的详细信息合并。我一直在研究stackoverflow和文档。但是，我仍然无法让我的代码工作。似乎我从子网站提取其他详细信息的功能不起作用。如果有人可以看看我会非常感激。

# -*- 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

我一直在看这些示例以及很多其他示例（stackoverflow很棒！），以及scrapy文档，但仍然无法理解我如何从一个函数发送详细信息并合并使用原始函数中的已删除项目。

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

Answer 1

您在这里看到的是被称为请求链。你的问题是 - 从几个请求中产生一个项目。解决此问题的方法是在请求meta属性中携带项目时链接请求例如：

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

Scrapy将subsite-item与site-item合并

1 个答案: