Scrapy链接已爬行但未刮擦

Posted 2021-04-06

我在电子商务网站Cdiscount上制作了一个刮刀来抓取与“au-quotidien”相关的所有类别。机器人应该从顶层菜单开始，然后访问第二层深层，然后是第三层，并刮取项目。这是我的代码，作为测试：

class CdiscountSpider(scrapy.Spider):
name = "cdis_bot"  # how we have to call the bot
start_urls = ["https://www.cdiscount.com/au-quotidien/v-127-0.html"]

def parse(self, response):
    for link in response.css('div.mvNavSub ul li a::attr(href)').extract():
        regex_top_category = r"(?=w)" + re.escape("au-quotidien") + r"(?!w)"
        if re.search(regex_top_category, link):
            yield response.follow(link, callback = self.parse_on_categories) #going to one layer deep from landing page

def parse_on_categories(self, response):
    for link in response.css('div.mvNavSub ul li a::attr(href)').extract():
        yield response.follow(link, callback = self.parse_on_subcategories) #going to two layer deep from landing page

def parse_on_subcategories(self, response):
    for link in response.css('div.mvNavSub ul li a::attr(href)').extract():
        yield response.follow(link, callback = self.parse_data) #going to three layer deep from landing page

def parse_data(self, response):
    links_list = response.css("div.prdtBILDetails a::attr(href)").extract()
    regex_ean = re.compile(r'(d+).html')
    eans_list = [regex_ean.search(link).group(1) for link in links_list if regex_ean.search(link)]
    desc_list = response.css("div.prdtBILTit::text").extract()
    price_euros = response.css("span.price::text").extract()
    price_cents = response.css("span.price sup::text").extract()
    for euro, cent, ean, desc in zip(price_euros, price_cents, eans_list, desc_list):
        if len(ean) > 6: 
             yield{'ean':ean,'price':euro+cent,'desc':desc,'company':"cdiscount",'url':response.url}

我的问题是，只检索链接。

例如 ：

2018-12-18 14:40:41 [scrapy.core.engine] DEBUG: Crawled (200) <GET https://www.cdiscount.com/au-quotidien/alimentaire/pates-riz-/legumes-secs/l-127015303.html> (referer: https://www.cdiscount.com/au-quotidien/alimentaire/pates-riz-/l-1270153.html)
2018-12-18 14:40:41 [scrapy.core.engine] DEBUG: Crawled (200) <GET https://www.cdiscount.com/au-quotidien/alimentaire/pates-riz-/semoules/l-127015302.html> (referer: https://www.cdiscount.com/au-quotidien/alimentaire/pates-riz-/l-1270153.html)

但我只得到很少的碎片，总是在同一类别，如下所示：

{'ean': '2009818241269', 'price': '96€00', 'desc': 'Heidsieck & Co Monopole  75cl x6', 'company': 'cdiscount', 'url': 'https://www.cdiscount.com/vin-champagne/vin-champagne/champagne-brut/l-1293402.html'}
2018-12-18 14:40:34 [scrapy.core.scraper] DEBUG: Scraped from <200 https://www.cdiscount.com/vin-champagne/vin-champagne/champagne-brut/l-1293402.html>

虽然在我看来，其他类别共享相同的项目选择器。

如果你能帮助我弄清楚我错在哪里，我将不胜感激:)谢谢

答案

看起来你的parse_data()方法收到的反应都差别很大。

例如，这些是它在示例运行中解析的前三个URL：

https://www.cdiscount.com/vin-champagne/vin-champagne/champagne-millesime/l-1293404.html
https://www.cdiscount.com/vin-champagne/coffrets-cadeaux/v-12960-12960.html
https://www.cdiscount.com/au-quotidien/alimentaire/bio/boisson-bio/jus-de-tomates-bio/l-12701271315.html

很明显（即使从快速浏览一下）每个页面的结构也不同。

在大多数情况下，你的eans_list和desc_list都是空的，所以zip()调用没有结果。