Ruby Nokogiri: Get class attribute of a TR element (or any other node for that matter)

get_element_class_name.rb

require 'nokogiri'

html = %q{
    <table>
        <tr class="even_class">
             <td></td>
        </tr>
        <tr class="odd_class">
            <td></td>
        </tr>
   </table>
  }

  doc = Nokogiri::HTML(html)
  rows = doc.xpath("//tr")
  rows.each do | row |
      puts row.attr('class')
  end