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我在抓这页https://www.library.uq.edu.au/uqlsm/availablepcsembed.php?branch=Duhig和每个tr
我正在收集并返回可用的计算机名称和数量。Nokogiri迭代tr标签太多次
问题在于它迭代了太多次。只有4个tr
标签,但循环经过5次迭代。这会导致额外的nil
被追加到返回数组。为什么是这样?
刮科:
<table class="chart">
<tr valign="middle">
<td class="left"><a href="availablepcsembed.php?branch=Duhig&room=Lvl1">Level 1</a></td>
<td class="middle"><div style="width:68%;"><strong>68%</strong></div></td>
<td class="right">23 Free of 34 PC's</td>
</tr>
<tr valign="middle">
<td class="left"><a href="availablepcsembed.php?branch=Duhig&room=Lvl2">Level 2</a></td>
<td class="middle"><div style="width:78%;"><strong>78%</strong></div></td>
<td class="right">83 Free of 107 PC's</td>
</tr>
<tr valign="middle">
<td class="left"><a href="availablepcsembed.php?branch=Duhig&room=Lvl4">Level 4</a></td>
<td class="middle"><div style="width:64%;"><strong>64%</strong></div></td>
<td class="right">9 Free of 14 PC's</td>
</tr>
<tr valign="middle">
<td class="left"><a href="availablepcsembed.php?branch=Duhig&room=Lvl5">Level 5</a></td>
<td class="middle"><div style="width:97%;"><strong>97%</strong></div></td>
<td class="right">28 Free of 29 PC's</td>
</tr>
</table>
缩短的方法:
def self.scrape_details_page(library_url)
details_page = Nokogiri::HTML(open(library_url))
library_name = details_page.css("h3")
details_page.css("table tr").collect do |level|
case level.css("a[href]").text.downcase
when "level 1"
name = level.css("a[href]").text
total_available = level.css(".right").text.split(" ")[0]
out_of_available = level.css(".right").text.split(" ")[3]
level = {name: name, total_available: total_available, out_of_available: out_of_available}
when "level 2"
name = level.css("a[href]").text
total_available = level.css(".right").text.split(" ")[0]
out_of_available = level.css(".right").text.split(" ")[3]
level = {name: name, total_available: total_available, out_of_available: out_of_available}
end
end
end