Scrapy - 按类别获取总数

Question

我试图获取Scrapy中每个网址的总计数（简单来说，对于以＆＃34开头的项目; A＆＃34;＆amp;＆＃34; B＆＃34; ）。我知道如何计算每个字母表的计数以及如何获得累积计数（两个网址的总计数）。但是如何获得每个链接/网址的总数？我想我已经接近但我无法弄明白。我错过了什么？

import scrapy
import string
import itertools

class AmazonitemsSpider(scrapy.Spider):
    name = 'amazonitems'
    allowed_domains = ['www.amazon.ca']
    def __init__(self):
        self.total_count = []
        self.f = open('csvfile.csv','w')

    def start_requests(self):
        alphabets = [ 'a', 'b' ]
        amazon_urls = [ 'https://www.amazon.ca/gp/search/other/?rh=i%2Cn%3A6647368011&pickerToList=lbr_brands_browse-bin&indexField=', 'https://www.amazon.ca/gp/search/other/?rh=i%2Cn%3A2224133011&pickerToList=lbr_brands_browse-bin&indexField=' ]
        for amazon_url in amazon_urls:
            keywords = itertools.product(alphabets, repeat=1)
            for keyword in keywords:
                keyword = ''.join(keyword)
                yield scrapy.Request(url=amazon_url + keyword, callback=self.parse)

    def parse(self, response):
        count_list = []
        items = response.xpath('//*[@class="a-list-item"]')
        for item in items:
            item_count = item.xpath('.//*[@class="narrowValue"]/text()').extract_first()
            item_count = item_count.replace('(','').replace(')','').strip()
            count_list.append(int(item_count))            
        count_list = sum(count_list)
        self.total_count.append(count_list)

    def closed(self, reason):
        self.total_count = sum(self.total_count)
        self.f.write(str(total_count) + '\n')
        self.f.close()