xml.etree.ElementTree.ParseError: not well-formed (invalid token) in Python
<p>I am trying to open an XML file using <code>ElementTree</code> but an error occurred: </p>

<blockquote>
  <p>xml.etree.ElementTree.ParseError: not well-formed (invalid token)</p>
</blockquote>

<p>And here is my code:</p>

<pre><code># -*- coding: utf-8 -*-
import xml.etree.ElementTree as etree

def main():
    tree = etree.parse('test.xml')
    print 'parsing Success!'

if __name__ == "__main__":
    main()
</code></pre>

<p>How can I fix this error?</p>