title: TypeError: writelines() argument must be a sequence of strings
body: <p>I have a weird error when try to redirect a exception to STDERR.</p>
  
  <p>I have a script that is use to load several "plugins", working as main entry program. The plugins do stuff like connect to databases, parsing text data, connect to web services, etc...</p>
  
  <p>Is like this:</p>
  
  <pre><code>   try:
          Run plugins here...
          #All was ok!
          print "Ok!"
          sys.exit(0)
      except Exception,e:
          sys.stderr.writelines([unicode(e),u'\n',u'\n'])
  
          traceback.print_exc(file=sys.stderr)
          sys.exit(-1)
  </code></pre>
  
  <p>This is executed in the command-line, and sometimes I get the error:</p>
  
  <pre><code>TypeError: writelines() argument must be a sequence of strings
  </code></pre>
  
  <p>I have no clue how in this earth a Exception is not returning as a string here.</p>