[FIXED] Scrapy links crawled but not scraped

Issue

I have made a scraper to crawl all categories related to "au-quotidien", on e-commerce website Cdiscount. The bot is supposed to start on the top menu, then accessing a second layer deep, then a third, and scrape items. Here is my code, as a test :

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"\b(?=\w)" + re.escape("au-quotidien") + r"\b(?!\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}

My problem is that, only links are retrieved.

For instance :

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)

But I get only a very few scraped items, always on the same category, like this :

{'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>

While it seems to me that other categories share the same items selector.

If you could help me to figure out where I am wrong I would be grateful :) thank you

Solution

It looks like the responses your parse_data() method is receiving are all vastly different.

For example, these are the first three urls it parses on a sample run:

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

It's obvious (even from a quick glance) that the structure of each of these pages is different.

In most cases, your eans_list and desc_list are empty, so the zip() call produces no results.

Answered By - stranac