我正在抓取Techcrunch.com,并获取每篇文章的标题,URL和预览文本。
我有:
require 'nokogiri'
require 'open-uri'
class TestScraper::Scraper
@doc = Nokogiri::HTML(open("https://techcrunch.com")
def scrape_tech_crunch
articles = @doc.css("h2.post-block__title").css("a")
top_stories = articles.each do |story|
stories = {
:title => story.children.text.strip,
:url => story.attribute("href").value,
:preview => @doc.css("div.post-block__content").children.first.text
}
TestScraper::Article.new(stories)
end
end
end
[TestScraper::Article.new(stories)
以哈希作为参数,并使用其初始化Article类:
class TestScraper::Article
attr_accessor :title, :url, :preview
@@all = []
def initialize(hash)
hash.each do |k, v|
self.send "#{k}=", v
end
@@all << self
end
def self.all
@@all
end
end
[当我运行TestScraper::Scraper.new("https://techcrunch.com").scrape_tech_crunch
时,我得到:
[#<TestScraper::Article:0x00000000015f69e0
@preview=
"\n\t\tSecurity researchers have found dozens of Android apps in the Google Play store serving ads to unsuspecting victims as part of a money-making scheme. ESET researchers found 42 apps conta
ining adware, \t",
@title=
"Millions downloaded dozens of Android apps on Google Play infected with adware",
@url=
"https://techcrunch.com/2019/10/24/millions-dozens-android-apps-adware/">,
#<TestScraper::Article:0x00000000015f5658
@preview=
"\n\t\tSecurity researchers have found dozens of Android apps in the Google Play store serving ads to unsuspecting victims as part of a money-making scheme. ESET researchers found 42 apps conta
ining adware, \t",
@title="Netflix launches $4 mobile-only monthly plan in Malaysia",
@url=
"https://techcrunch.com/2019/10/24/netflix-malaysia-mobile-only-cheap-plan/">
它会为文章类的每个实例创建一个具有适当标题和URL的对象,但会继续为每个文章实例分配相同的预览文本。应该有20篇文章,每篇文章都有自己的“预览”(在单击链接以阅读全文之前,您会获得该文章的小样本)。
您遇到的问题是由于以下事实:>
@doc.css("div.post-block__content").children.first.text
为每个故事选择相同的节点,因为您在全局文档
@doc
上对其进行了调用。
而不是尝试找到最常见的节点,然后从那里向下走:
@doc.css('.post-block').map do |story| # navigate down from the selected node title = story.at_css('h2.post-block__title a') preview = story.at_css('div.post-block__content') TestScraper::Article.new( title: title.content.strip, href: title['href'], preview: preview.content.strip ) end
[如果任何使用的方法引起问题,请查看Nokogiri cheat sheet。如果您在此之后有任何疑问,请不要在评论中提出疑问。