title: Lxml error when parsing kml using pykml
body: <p>Im trying to parse a kml file containing multiple placemarks using pykml. I want to edit the HTML code inside the kml's description, mainly for visualization purposes of geographic data in Google Earth. Ive researched a lot of ways to do so:</p>
  
  <ul>
  <li><a href="https://stackoverflow.com/questions/13712132/extract-coordinates-from-kml-batchgeo-file-with-python">Extract Coordinates from KML BatchGeo File with Python</a></li>
  <li><a href="https://stackoverflow.com/questions/33321223/read-kml-file-with-multiple-placemarks-in-pykml?newreg=9a9cc9d40c2a493fb3117c071ce87c6d">Read kml file with multiple placemarks in pykml</a></li>
  <li><a href="https://stackoverflow.com/questions/26074069/using-pykml-to-parse-kml-document">Using pyKML to parse KML Document</a></li>
  <li><a href="https://stackoverflow.com/questions/7821977/kml-to-string-in-python">KML to string in Python?</a></li>
  </ul>
  
  <p>however, I always get the lxml error shown below. :(</p>
  
  <pre><code>    Traceback (most recent call last):
      File "C:\Users\Arellano\Copy\BSGE\2015-2016 SUMMER\trial7.py", line 5, in &lt;module&gt;
      root = parser.fromstring(open('trim_KML.kml', 'r').read())
    File "C:\Program Files (x86)\Python2.7.10\lib\site-packages\pykml-0.1.0-py2.7.egg\pykml\parser.py", line 41, in fromstring
      return objectify.fromstring(text)
    File "src/lxml/lxml.objectify.pyx", line 1801, in lxml.objectify.fromstring (src\lxml\lxml.objectify.c:25171)
    File "src/lxml/lxml.etree.pyx", line 3213, in lxml.etree.fromstring (src\lxml\lxml.etree.c:77697)
    File "src/lxml/parser.pxi", line 1819, in lxml.etree._parseMemoryDocument (src\lxml\lxml.etree.c:116494)
    File "src/lxml/parser.pxi", line 1707, in lxml.etree._parseDoc (src\lxml\lxml.etree.c:115144)
    File "src/lxml/parser.pxi", line 1079, in lxml.etree._BaseParser._parseDoc (src\lxml\lxml.etree.c:109543)
    File "src/lxml/parser.pxi", line 573, in lxml.etree._ParserContext._handleParseResultDoc (src\lxml\lxml.etree.c:103404)
    File "src/lxml/parser.pxi", line 683, in lxml.etree._handleParseResult (src\lxml\lxml.etree.c:105058)
    File "src/lxml/parser.pxi", line 613, in lxml.etree._raiseParseError (src\lxml\lxml.etree.c:103967)
  XMLSyntaxError: Namespace prefix xsi for schemaLocation on Document is not defined, line 3, column 32
  </code></pre>
  
  <p>Heres my code snippet: (which is supposed to work based from one of my sources)</p>
  
  <pre><code>from pykml import parser
  
  root = parser.fromstring(open('trim_KML.kml', 'r').read())
  print etree.tostring(root.Document.Placemark.LineString.Description)
  </code></pre>
  
  <p>I have installed pykml and lxml 3.6.0 and Im currently using my Python 2.7.10. The kml file contains lines. (kml link: <a href="https://sites.google.com/site/kmlhostingmwss/trim.kml" rel="nofollow noreferrer">https://sites.google.com/site/kmlhostingmwss/trim.kml</a>)
  I also have Python 2.7 from my ArcGIS 10.2. </p>
  
  <p>Im new with working with kml files. Can someone please tell me what am I doing wrong? Or is there an easier way to edit the description of kml files? Thank you very much. :)))</p>