使用 Ruby / Nokogiri 解析随机类名

Question

我一直在手工计算各个州的美国总统选举投票的剩余百分比。有这么多的更新和状态——这越来越累了。那么为什么不自动化这个过程呢？

这是我正在查看的内容：

问题是类名是随机的。例如，这是我感兴趣的：
<td class="jsx-3768461732 votes votes-row">2,450,186</td>

在 irb 中玩耍，我尝试在“votes votes-row”上使用通配符，因为这仅在我需要在文档中出现时出现：

require 'nokogiri'
require 'open-uri'
doc = Nokogiri::HTML(open("https://www.politico.com/2020-election/results/georgia/"))
votes = doc.css("[td*='votes-row']")

...没有结果 (=> [])

我做错了什么以及如何解决？我对 xpath 没意见——我只是想确保在文档中其他地方所做的更改不会影响找到这些元素。

Answer 1

可能有更好的方法，但是...

require 'nokogiri'
require 'open-uri'
doc = Nokogiri::HTML(open("https://www.politico.com/2020-election/results/georgia/"))
votes = doc.css('tr[class*="candidate-row"]').map { |row| row.css('td').map { |cell| cell.content } }
biden_row = votes.find_index { |row| row[0] =~ /biden/i }
trump_row = votes.find_index { |row| row[0] =~ /trump/i }
biden_votes = votes[biden_row][1].split('%')[1]
trump_votes = votes[trump_row][1].split('%')[1]

编辑：来自 HTML 源代码的相关表格如下所示：

<table class="jsx-1526769828 candidate-table">
  <thead class="jsx-3554868417 table-head">
    <tr class="jsx-3554868417">
      <th class="table-header jsx-3554868417 candidate-name">
        <h5 class="jsx-3554868417">Candidate</h5>
      </th>
      <th class="table-header jsx-3554868417 percent">
        <h5 class="jsx-3554868417">Pct.</h5>
      </th>
      <th class="table-header jsx-3554868417 vote-bar"></th>
    </tr>
  </thead>
  <tbody class="jsx-2085888330 table-head">
    <tr class="jsx-2677388595 candidate-row">
      <td class="jsx-3948343365 candidate-name name-row">
        <div class="jsx-1912693590 name-only candidate-short-name">Biden</div>
        <div class="jsx-3948343365 candidate-party-tag">
          <div class="jsx-1420258095 party-label dem">dem</div>
        </div>
        <div class="jsx-3948343365 candidate-winner-check"></div>
      </td>
      <td class="jsx-3830922081 percent percent-row">
        <div class="candidate-percent-only jsx-3830922081">49.4%</div>
        <div class="candidate-votes-next-to-percent jsx-3830922081">2,450,193</div>
      </td>
      <td class="jsx-3458171655 vote-bar vote-bar-row">
        <div style="width:49.4%" class="jsx-3458171655 bar dem"></div>
      </td>
    </tr>
    <tr class="jsx-2677388595 candidate-row">
      <td class="jsx-3948343365 candidate-name name-row">
        <div class="jsx-1912693590 name-only candidate-short-name">Trump*</div>
        <div class="jsx-3948343365 candidate-party-tag">
          <div class="jsx-1420258095 party-label gop">gop</div>
        </div>
        <div class="jsx-3948343365 candidate-winner-check"></div>
      </td>
      <td class="jsx-3830922081 percent percent-row">
        <div class="candidate-percent-only jsx-3830922081">49.4%</div>
        <div class="candidate-votes-next-to-percent jsx-3830922081">2,448,635</div>
      </td>
      <td class="jsx-3458171655 vote-bar vote-bar-row">
        <div style="width:49.4%" class="jsx-3458171655 bar gop"></div>
      </td>
    </tr>
  </tbody>
</table>

因此，您可能可以使用候选投票的下一个百分比来获得该值。例如：

require 'nokogiri'
require 'open-uri'
doc = Nokogiri::HTML(open("https://www.politico.com/2020-election/results/georgia/"))
votes = doc.css('tr[class*="candidate-row"]').map do |row|
  [
    row.css('div[class*="candidate-short-name"]').first.content,
    row.css('div[class*="candidate-votes-next-to-percent"]').first.content
  ]
end
# => [["Biden", "2,450,193"], ["Trump*", "2,448,635"]]