title: Python TimedRotatingFileHandler logs to a file and stderr
body: <p>I am trying to include simple logging into my application using TimedRotatingFileHandler. However I get the output both into the designated file and into the standard error. I reduced the problem to a small example:</p>
  
  <pre><code>import logging, logging.handlers
  import sys
  
  logging.basicConfig(format='%(asctime)s %(message)s')
  loghandler = logging.handlers.TimedRotatingFileHandler("logfile",when="midnight")
  logger = logging.getLogger()
  logger.setLevel(logging.INFO)
  logger.addHandler(loghandler)
  
  for k in range(5):
      logger.info("Line %d" %  k)
  </code></pre>
  
  <p>I get 5 log lines both in my 'logfile' and this program's stderr.  What am I doing wrong?</p>