如何在具有不同内容的网站中废弃容器？

Posted 2021-03-28

我想废弃这个网站。 https://www.dhgate.com/wholesale/electronics-robots/c103032.html

我已经构建了一个scrapy代码：

import scrapy
from urllib.parse import urljoin



class DhgateSpider(scrapy.Spider):
    name = 'dhgate'
    allowed_domains = ['dhgate.com']
    start_urls = ['https://www.dhgate.com/wholesale/electronics-robots/c103032.html']


    def parse(self, response):
        Product = response.xpath('//*[@class="pro-title"]/a/@title').extract()
        Price = response.xpath('//*[@class="price"]/span/text()').extract()
        Customer_review = response.xpath('//*[@class="reviewnum"]/span/text()').extract()
        Seller = response.xpath('//*[@class="seller"]/a/text()').extract()
        Feedback = response.xpath('//*[@class="feedback"]/span/text()').extract()

        for item in zip(Product,Price,Customer_review,Seller,Feedback):
            scraped_info = {
                'Product':item[0],
                'Price': item[1],
                'Customer_review':item[2],
                'Seller':item[2],
                'Feedback':item[3],

            }
            yield scraped_info
        next_page_url = response.xpath('//*[@class="next"]/@href').extract_first()
        if next_page_url:
            next_page_url = urljoin('https:',next_page_url)
            yield scrapy.Request(url = next_page_url, callback = self.parse)

问题是并非每个容器都有客户审核或反馈项。因此，它只会废弃那些具有完整产品，价格，customer_review，卖家和反馈项目的产品。我想废弃所有容器，哪里没有customer_review，我想添加一个空值。我怎么做？谢谢。

答案

不要使用zip：

def parse(self, response):

    for product_node in response.xpath('//div[@id="proList"]/div[contains(@class, "listitem")]'):
        Product = product_node.xpath('.//*[@class="pro-title"]/a/@title').extract_first()
        Price = product_node.xpath('.//*[@class="price"]/span/text()').extract_first()
        Customer_review = product_node.xpath('.//*[@class="reviewnum"]/span/text()').extract_first()
        Seller = product_node.xpath('.//*[@class="seller"]/a/text()').extract_first()
        Feedback = product_node.xpath('.//*[@class="feedback"]/span/text()').extract_first()

        scraped_info = {
                'Product':Product,
                'Price': Price,
                'Customer_review':Customer_review,
                'Seller':Seller,
                'Feedback':Feedback,
        }
        yield scraped_info

    next_page_url = response.xpath('//*[@class="next"]/@href').extract_first()
    if next_page_url:
        next_page_url = urljoin('https:',next_page_url)
        yield scrapy.Request(url = next_page_url, callback = self.parse)