title: Replacement of an ampersand in xml document after encodings/decodings
body: <p>How do i replace a amphersand with the html sign &amp; in a xml document?
  normally it works simply with  </p>
  
  <pre><code>a = u"TORE &amp; Co &amp; KG"
  i = a.replace('&amp;','&amp;amp;')
  print i 
  </code></pre>
  
  <p>Here it doesn't work:i get my xml structure out of an email and process it like this:</p>
  
  <pre><code>saver=StringIO(u"") # Edit
  a=str(msg)
  i= a.decode('quopri').decode('utf-8')
  saver.write(i)
  savercontent = saver.getvalue()
  savercontent.replace('&amp;','&amp;amp;') 
  </code></pre>
  
  <p>In the end the replacement dosen't work...no errors..., how can i fix this? I guess this is connected with the encodings/decodings... Any help?</p>