title: obtain en-US title tag text
body: <p>I'm trying to obtain the text in only the title@lang=en-US elements in an XML file. 
  This code obtains all the title text for all languages. </p>
  
  <pre><code>entries = root.xpath('//prefix:new-item', namespaces={'prefix': 'http://mynamespace'})
  for entry in entries: 
      all_titles = entry.xpath('./prefix:title', namespaces={'prefix': 'http://mynamespace'})
      for title in all_titles:
         print (title.text)
  </code></pre>
  
  <p>I tried this code to get the title@lang=en-US text, but it does not work. </p>
  
  <pre><code>all_titles = entry.xpath('./prefix:title', namespaces={'prefix': 'http://mynamespace'})
  for title in all_titles:
    test = title.xpath("@lang='en-US'")
    print (test)
  </code></pre>
  
  <p>How do I obtain the text for only the english language items?</p>