title: How to deal with "lxml.etree.XMLSyntaxError"?
body: <p>When I use <code>lxml.etree</code> to parse some page, it occurs errors like following</p>
  
  <pre><code>lxml.etree.XMLSyntaxError: Double hyphen within comment: &lt;!--[if lte IE 9 ]&gt;
  </code></pre>
  
  <p>the page's head code is like</p>
  
  <pre><code>&lt;!--[if lt IE 7 ]&gt;&lt;html class="ie6 domain_so"&gt;&lt;![endif]--&gt;
  &lt;!--[if IE 7 ]&gt;&lt;html class="ie7 domain_so"&gt;&lt;![endif]--&gt;
  &lt;!--[if IE 8 ]&gt;&lt;html class="ie8 domain_so"&gt;&lt;![endif]--&gt;
  &lt;!--[if IE 9 ]&gt;&lt;html class="ie9 domain_so"&gt;&lt;![endif]--&gt;
  &lt;!--[if (gt IE 9)|!(IE)]&gt;&lt;!--&gt;&lt;html class="w3c domain_so"&gt;&lt;!--&lt;![endif]--&gt;
  </code></pre>
  
  <p>How to handle this?</p>