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问如何在Nokogiri中获得独特的链接
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Stack Overflow用户

提问于 2013-08-27 17:09:33

回答 3查看 339关注 0票数 0

我有下面的html，它有两个重复的href。

<div class="pages">
  <a href="/search_results.aspx?f=Technology&Page=1" class="active">1</a>
  <a href="/search_results.aspx?f=Technology&Page=2">2</a>
  <a href="/search_results.aspx?f=Technology&Page=3">3</a>
  <a href="/search_results.aspx?f=Technology&Page=4">4</a>
  <a href="/search_results.aspx?f=Technology&Page=5">5</a>
  <a href="/search_results.aspx?f=Technology&Page=2">next &rsaquo;</a>
  <a href="/search_results.aspx?f=Technology&Page=6">last &raquo;</a>
</div> 

# p => is the page that has this html
# The below gives 7 as expected. But I don't need next/last links as they are duplicate    
p.css(".pages a").count

#So I tried uniq which obviously didnt work

p.css(".pages").css("a").uniq            #=> didn't work
p.css(".pages").css("a").to_a.uniq       #=> didn't work

ruby

nokogiri

回答 3

Stack Overflow用户

回答已采纳

发布于 2013-08-27 17:16:37

尝试从匹配元素(el.attr('href'))中提取"href“属性：

html = Nokogiri::HTML(your_html_string)
html.css('a').map { |el| el.attr('href') }.uniq
# /search_results.aspx?f=Technology&Page=1
# /search_results.aspx?f=Technology&Page=2
# /search_results.aspx?f=Technology&Page=3
# /search_results.aspx?f=Technology&Page=4
# /search_results.aspx?f=Technology&Page=5
# /search_results.aspx?f=Technology&Page=6

票数 4

Stack Overflow用户

发布于 2013-08-27 18:17:05

使用#xpath也可以这样做。以下是我要做的：

require 'nokogiri'

doc = Nokogiri::HTML::Document.parse <<-HTML
<div class="pages">
  <a href="/search_results.aspx?f=Technology&Page=1" class="active">1</a>
  <a href="/search_results.aspx?f=Technology&Page=2">2</a>
  <a href="/search_results.aspx?f=Technology&Page=3">3</a>
  <a href="/search_results.aspx?f=Technology&Page=4">4</a>
  <a href="/search_results.aspx?f=Technology&Page=5">5</a>
  <a href="/search_results.aspx?f=Technology&Page=2">next &rsaquo;</a>
  <a href="/search_results.aspx?f=Technology&Page=6">last &raquo;</a>
</div> 
HTML

doc.xpath("//a/@href").map(&:to_s).uniq
# => ["/search_results.aspx?f=Technology&Page=1",
#     "/search_results.aspx?f=Technology&Page=2",
#     "/search_results.aspx?f=Technology&Page=3",
#     "/search_results.aspx?f=Technology&Page=4",
#     "/search_results.aspx?f=Technology&Page=5",
#     "/search_results.aspx?f=Technology&Page=6"]

票数 3

Stack Overflow用户

发布于 2013-08-27 18:37:59

执行相同工作的另一种方法是在xpath表达式本身中处理uniq值选择：

require 'nokogiri'

doc = Nokogiri::HTML::Document.parse <<-HTML
<div class="pages">
  <a href="/search_results.aspx?f=Technology&Page=1" class="active">1</a>
  <a href="/search_results.aspx?f=Technology&Page=2">2</a>
  <a href="/search_results.aspx?f=Technology&Page=3">3</a>
  <a href="/search_results.aspx?f=Technology&Page=4">4</a>
  <a href="/search_results.aspx?f=Technology&Page=5">5</a>
  <a href="/search_results.aspx?f=Technology&Page=2">next &rsaquo;</a>
  <a href="/search_results.aspx?f=Technology&Page=6">last &raquo;</a>
</div> 
HTML

doc.xpath("//a[not(@href = preceding-sibling::a/@href)]/@href").map(&:to_s)
# => ["/search_results.aspx?f=Technology&Page=1",
#     "/search_results.aspx?f=Technology&Page=2",
#     "/search_results.aspx?f=Technology&Page=3",
#     "/search_results.aspx?f=Technology&Page=4",
#     "/search_results.aspx?f=Technology&Page=5",
#     "/search_results.aspx?f=Technology&Page=6"]

票数 0

页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持

原文链接：

https://stackoverflow.com/questions/18471613

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