Question

我正在使用scrapy来收集一些数据。我的scrapy程序在一个会话中收集100个元素。我需要将它限制为50或任何随机数。我怎样才能做到这一点？欢迎任何解决方案。提前致谢

# -*- coding: utf-8 -*-
import re
import scrapy


class DmozItem(scrapy.Item):
    # define the fields for your item here like:
    link = scrapy.Field()
    attr = scrapy.Field()
    title = scrapy.Field()
    tag = scrapy.Field()


class DmozSpider(scrapy.Spider):
    name = "dmoz"
    allowed_domains = ["raleigh.craigslist.org"]
    start_urls = [
        "http://raleigh.craigslist.org/search/bab"
    ]

    BASE_URL = 'http://raleigh.craigslist.org/'

    def parse(self, response):
        links = response.xpath('//a[@class="hdrlnk"]/@href').extract()
        for link in links:
            absolute_url = self.BASE_URL + link
            yield scrapy.Request(absolute_url, callback=self.parse_attr)

    def parse_attr(self, response):
        match = re.search(r"(\w+)\.html", response.url)
        if match:
            item_id = match.group(1)
            url = self.BASE_URL + "reply/ral/bab/" + item_id

            item = DmozItem()
            item["link"] = response.url
            item["title"] = "".join(response.xpath("//span[@class='postingtitletext']//text()").extract())
            item["tag"] = "".join(response.xpath("//p[@class='attrgroup']/span/b/text()").extract()[0])
            return scrapy.Request(url, meta={'item': item}, callback=self.parse_contact)

    def parse_contact(self, response):
        item = response.meta['item']
        item["attr"] = "".join(response.xpath("//div[@class='anonemail']//text()").extract())
        return item

Answer 1

这是CloseSpider extension和CLOSESPIDER_ITEMCOUNT设置的目的：

一个整数，指定多个项目。如果蜘蛛擦伤如果项目和项目通过项目，则超过该数量管道，蜘蛛将被关闭的原因 closespider_itemcount。如果为零（或未设置），则不会关闭蜘蛛按已通过的项目数量。

Answer 2

我尝试了alecxe的答案，但是我必须结合所有三个限制来使其起作用，因此将其留在此处以防其他人遇到相同的问题：

class GenericWebsiteSpider(scrapy.Spider):
    """This generic website spider extracts text from websites"""

    name = "generic_website"

    custom_settings = {
        'CLOSESPIDER_PAGECOUNT': 15,
        'CONCURRENT_REQUESTS': 15,
        'CLOSESPIDER_ITEMCOUNT': 15
    }
...

限制scrapy可以收集多少元素

2 个答案: