从HTML中抓取跟踪数据？

Question

我希望能够在1001Tracklist上从跟踪列表页面中抓取数据。URL示例是：

http://www.1001tracklists.com/tracklist/25122_lange-intercity-podcast-115-2013-03-06.html

下面是一个如何在页面上显示数据的示例：

Above & Beyond - Black Room Boy (Above & Beyond Club Mix) [ANJUNABEATS]

我想以以下格式从这个页面中取出所有的歌曲：

$byArtist - $name [$publisher]

在查看了此页面的HTML之后，显示我所追求的内容以HTML5元数据格式存储：

<td class="" id="tlptr_433662">
<a name="tlp_433662"></a>
<div itemprop="tracks" itemscope itemtype="http://schema.org/MusicRecording" id="tlp5_content">
<meta itemprop="byArtist" content="Above &amp; Beyond">
<meta itemprop="name" content="Black Room Boy (Above &amp; Beyond Club Mix)">
<meta itemprop="publisher" content="ANJUNABEATS">
<meta itemprop="url" content="/track/103905_above-beyond-black-room-boy-above-beyond-club-mix/index.html">
<span class="tracklistTrack floatL"id="tr_103905" ><a href="/track/103905_above-beyond-black-room-boy-above-beyond-club-mix/index.html" class="">Above &amp; Beyond - Black Room Boy (Above &amp; Beyond Club Mix)</a>&thinsp;</span><span class="floatL">[<a href="/label/1037_anjunabeats/index.html" title="Anjunabeats">ANJUNABEATS</a>]</span>  
<div id="tlp5_actions" class="floatL" style="margin-top:1px;">

有一个具有"tlp_433662“值的CSS选择器。页面上的每首歌都会有自己独特的标识。一个是"tlp_433662“，另一个是"tlp_433628”或类似的东西。

是否有一种方法可以使用Nokogiri和XPath提取跟踪列表页面中列出的所有歌曲？我可能希望在下面列出的“数据”上“做”一个“每个”，这样刮刀就会循环在数据上，提取每一组相关数据。下面是我的Ruby程序的开始：

require 'rubygems'
require 'nokogiri'
require 'open-uri'

url = "http://www.1001tracklists.com/tracklist/25122_lange-intercity-podcast-115-2013-03-06.html"
data = Nokogiri::HTML(open(url))
# what do do next? print out xpath loop code which extracts my data.
# code block I need help with
data.xpath.........each do |block|
block.xpath("...........").each do |span|
    puts stuff printing out what I want.
end
end

我的最终目标，我知道如何做，是把这个Ruby脚本到辛纳屈"webify“数据，并添加一些很好的Twitter引导CSS，如这个youtube视频所示：http://www.youtube.com/watch?v=PWI1PIvy4A8

您能帮我处理XPath代码块吗?这样我就可以刮掉数据并打印数组了吗？

Answer 1

require 'nokogiri'
require 'rest-client'

url = 'http://www.1001tracklists.com/tracklist/25122_lange-intercity-podcast-115-2013-03-06.html'
page = Nokogiri::HTML(RestClient.get(url,:user_agent=>'Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)'), nil, 'UTF-8');

page.css('table.detail tr.tlpItem').each do |row|
  artist = row.css('meta[@itemprop="byArtist"]').attr('content')
  name = row.css('meta[@itemprop="name"]').attr('content')

  puts "#{artist} - #{name}"
end

...a更高级的版本，它从行中获取所有元信息，并打印“艺术家-宋”出版商。

require 'nokogiri'
require 'rest-client'

url = 'http://www.1001tracklists.com/tracklist/25122_lange-intercity-podcast-115-2013-03-06.html'
page = Nokogiri::HTML(RestClient.get(url,:user_agent=>'Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)'), nil, 'UTF-8');

page.css('table.detail tr.tlpItem').each do |row|

  meta  = row.search('meta').each_with_object({}) do |tag, hash|
    hash[tag['itemprop']] = tag['content']
  end

  puts "#{meta['byArtist']} - #{meta['name']} [#{meta['publisher']||'Unknown'}]"
end

你就能得到剩下的房产的照片。您需要做一些错误/存在吗？检查，因为有些歌曲没有所有的属性。但这应该能让你走上正确的轨道。我也使用了rest-client创业板，所以您可以随意使用任何您想要检索的页面。

Answer 2

下面是一些代码，用于将信息收集到散列数组中。

我更喜欢使用CSS访问器，而不是XPath，因为如果您有任何HTML/CSS或jQuery经验，它们更容易读懂。

require 'nokogiri'
require 'open-uri'

doc = Nokogiri::HTML(open('http://www.1001tracklists.com/tracklist/25122_lange-intercity-podcast-115-2013-03-06.html'))
data = doc.search('tr.tlpItem div[itemtype="http://schema.org/MusicRecording"]').each_with_object([]) do |div, array|
  hash = div.search('meta').each_with_object({}) do |m, h|
    h[m['itemprop']] = m['content']
  end

  link = div.at('span a')
  hash['tracklistTrack'] = [ link['href'], link.text ]

  title = div.at('span.floatL a')
  hash['title'] = [title['href'], title.text ]

  array << hash
end

pp data[0, 2]

它输出页面数据的子集。经过一些按摩后，结构如下所示：

[
  {
    "byArtist"=>"Markus Schulz",
    "name"=>"The Spiritual Gateway (Transmission 2013 Theme)",
    "publisher"=>"COLDHARBOUR RECORDINGS",
    "url"=>"/track/108928_markus-schulz-the-spiritual-gateway-transmission-2013-theme/index.html",
    "tracklistTrack"=>[
        "/track/108928_markus-schulz-the-spiritual-gateway-transmission-2013-theme/index.html",
        "Markus Schulz - The Spiritual Gateway (Transmission 2013 Theme)"
      ],
    "title"=>[
      "/track/108928_markus-schulz-the-spiritual-gateway-transmission-2013-theme/index.html",
      "Markus Schulz - The Spiritual Gateway (Transmission 2013 Theme)"
    ]
  },
  {
    "byArtist"=>"Lange & Audrey Gallagher",
    "name"=>"Our Way Home (Noah Neiman Remix)",
    "publisher"=>"LANGE RECORDINGS",
    "url"=>"/track/119667_lange-audrey-gallagher-our-way-home-noah-neiman-remix/index.html",
    "tracklistTrack"=>[
      "/track/119667_lange-audrey-gallagher-our-way-home-noah-neiman-remix/index.html",
      "Lange & Audrey Gallagher - Our Way Home (Noah Neiman Remix)"
    ],
    "title"=>[
      "/track/119667_lange-audrey-gallagher-our-way-home-noah-neiman-remix/index.html",
      "Lange & Audrey Gallagher - Our Way Home (Noah Neiman Remix)"
    ]
  }
]

Answer 3

这里有一个免费的webservice ()从给定的url中抓取所有的400+ schema.org类，并将它们作为JSON返回。

http://scrappy.netfluid.org/