title: Python XPath keeps returning empty list
body: <p>XPath via lxml in Python has been making me run in circles. I can't get it to extract text from an HTML table despite having what I believe to be the correct XPath. I'm using Chrome to inspect and extract the XPath, then using it in my code.</p>
  
  <p>Here is the HTML table taken directly from the page:</p>
  
  <pre><code>&lt;div id="vehicle-detail-model-specs-container"&gt;
  &lt;table id="vehicle-detail-model-specs" class="table table-striped vdp-feature-table"&gt;
      &lt;!-- Price --&gt;
      &lt;tr&gt;
                  &lt;td&gt;&lt;strong&gt;Price:&lt;/strong&gt;&lt;/td&gt;
                      &lt;td&gt;
                              &lt;strong id="vehicle-detail-price" itemprop="price"&gt;$ 2,210.00&lt;/strong&gt;            &lt;/td&gt;
              &lt;/tr&gt;
                      &lt;!-- VIN --&gt;
      &lt;tr&gt;&lt;td&gt;&lt;strong&gt;VIN&lt;/strong&gt;&lt;/td&gt;&lt;td&gt;&amp;nbsp;*0343&lt;/td&gt;&lt;/tr&gt;
  
      &lt;!-- MILEAGE --&gt;
      &lt;tr&gt;&lt;td&gt;&lt;strong&gt;Mileage&lt;/strong&gt;&lt;/td&gt;&lt;td&gt;0&amp;nbsp;mi&lt;/td&gt;&lt;/tr&gt;
  &lt;/table&gt;
  </code></pre>
  
  <p></p>
  
  <p>I'm trying to extract the Mileage. The XPath I'm using is:</p>
  
  <pre><code>//*[@id="vehicle-detail-model-specs"]/tbody/tr[3]/td[2]
  </code></pre>
  
  <p>And the Python code that I'm using is:</p>
  
  <pre><code>page = requests.get(URL)
  tree = html.fromstring(page.content)
  
  mileage = tree.xpath('//*[@id="vehicle-detail-model-specs"]/tbody/tr[3]/td[2]')
  print mileage
  </code></pre>
  
  <p>Note: I've tried adding <code>/text()</code> to the end and I still get nothing back, just an empty list [].</p>
  
  <p>What am I doing wrong and why am I not able to extract the table value from the above examples?</p>