使用xpath和scrapy从HTML中提取特定值

Question

我有以下HTML代码：

<tr data-live="COumykPG" data-dt="10,11,2017,19,00" data-def="1">
<td class="table-matches__tt"><span class="table-matches__time" data-live-cell="time">19:00</span><a href="/soccer/germany/oberliga-bremen/oberneuland-habenhauser/COumykPG/" data-live-cell="matchlink"><span>Oberneuland</span> - <span>Habenhauser</span></a></td>
<td class="livebet" data-live-cell="livebet">&nbsp;</td>
<td class="table-matches__streams" data-live-cell="score">
</td>
<td class="table-matches__odds" data-oid="2p2k5xv464x0x6ev9v"><a href="/myselections.php?action=3&amp;matchid=COumykPG&amp;outcomeid=2p2k5xv464x0x6ev9v&amp;otheroutcomes=2p2k5xv498x0x0,2p2k5xv464x0x6eva0" onclick="return my_selections_click('1x2', 'soccer');" title="Add to My Selections" target="mySelections">1.10</a></td>
<td class="table-matches__odds" data-oid="2p2k5xv498x0x0"><a href="/myselections.php?action=3&amp;matchid=COumykPG&amp;outcomeid=2p2k5xv498x0x0&amp;otheroutcomes=2p2k5xv464x0x6ev9v,2p2k5xv464x0x6eva0" onclick="return my_selections_click('1x2', 'soccer');" title="Add to My Selections" target="mySelections">7.44</a></td>
<td class="table-matches__odds" data-oid="2p2k5xv464x0x6eva0"><a href="/myselections.php?action=3&amp;matchid=COumykPG&amp;outcomeid=2p2k5xv464x0x6eva0&amp;otheroutcomes=2p2k5xv464x0x6ev9v,2p2k5xv498x0x0" onclick="return my_selections_click('1x2', 'soccer');" title="Add to My Selections" target="mySelections">12.40</a></td>
</tr>

我尝试从以下代码中删除3个浮点值：1,10 7.44 12.40 我试图用来设置值的表达式如下：

response.xpath('//a/@target').extract()

我得到的输出是'mySelections'。

我希望得到旁边的价值。什么是正确的表达方式？

提前谢谢

Answer 1

出了什么问题

response.xpath（＆＃39; // A /的 @target ＆＃39）。提取物（）

为什么？

• 如果格式化HTML，则错误很明显。

    

  您想从text代码中提取a，而不是target属性。

          <tr data-live="COumykPG" data-dt="10,11,2017,19,00" data-def="1">
             <td class="table-matches__tt">
                <span class="table-matches__time" data-live-cell="time">19:00</span>
                <a href="/soccer/germany/oberliga-bremen/oberneuland-habenhauser/COumykPG/" data-live-cell="matchlink">
                <span>Oberneuland</span> - <span>Habenhauser</span>
                </a>
             </td>
             <td class="livebet" data-live-cell="livebet">&nbsp;</td>
             <td class="table-matches__streams" data-live-cell="score"></td>
             <td class="table-matches__odds" data-oid="2p2k5xv464x0x6ev9v">
  
             <a href="/myselections.php?action=3&amp;matchid=COumykPG&amp;outcomeid=2p2k5xv464x0x6ev9v&amp;otheroutcomes=2p2k5xv498x0x0,2p2k5xv464x0x6eva0" 
                onclick="return my_selections_click('1x2', 'soccer');" 
                title="Add to My Selections" 
                target="mySelections">1.10</a>
  
             </td>
             <td class="table-matches__odds" data-oid="2p2k5xv498x0x0">
  
             <a href="/myselections.php?action=3&amp;matchid=COumykPG&amp;outcomeid=2p2k5xv498x0x0&amp;otheroutcomes=2p2k5xv464x0x6ev9v,2p2k5xv464x0x6eva0" 
                onclick="return my_selections_click('1x2', 'soccer');" 
                title="Add to My Selections" 
                target="mySelections">7.44</a>
  
             </td>
             <td class="table-matches__odds" data-oid="2p2k5xv464x0x6eva0">
  
             <a href="/myselections.php?action=3&amp;matchid=COumykPG&amp;outcomeid=2p2k5xv464x0x6eva0&amp;otheroutcomes=2p2k5xv464x0x6ev9v,2p2k5xv498x0x0" 
                onclick="return my_selections_click('1x2', 'soccer');" 
                title="Add to My Selections" 
                target="mySelections">12.40</a>
  
             </td>
          </tr>
  

  如何解决

• 使用以下其中一项

  • response.xpath('//a/text()').extract()

  • 根据其他开发人员的说法，response.xpath有时会导致错误，您应该使用scrapy's selector。

    from scrapy.selector import Selector
    result_array = Selector(text=response.body).xpath('//a/text()').extract()