title: How do I specify a namespace for an xml tag with BeautifulSoup4?
body: <p>I'm using beautifulsoup4 like this:</p>
  
  <pre><code>from bs4 import BeautifulSoup
  xml_string = u"""&lt;something&gt;&lt;dcterms:valid&gt;&lt;![CDATA[
  
              start=2012-02-24T00:00:00Z
              end=2030-12-30T00:00:00Z
              scheme=W3C-DTF]]&gt;
          &lt;/dcterms:valid&gt;&lt;/something&gt;"""
  soup = BeautifulSoup(xml_string, 'xml')
  soup.find('dcterms:valid')  # returns None
  soup.find('valid')  # returns the dcterms:valid node
  </code></pre>
  
  <p>Is there a way to specify the namespace in the <code>soup.find(tagname)</code> so I can be precise about what I'm looking to find?</p>