title: Python logging to file through ini creates empty log file
body: <p>I have what I <em>think</em> is a very basic example of logging in Python (v2.7.10), but I cannot get logging to a file to work.  Logging to stderr is not a problem, but when I try to ask it to write to a file all I get is an empty log file.</p>
  
  <p>Here is my configuration <code>log_config.ini</code> file:</p>
  
  <pre><code>[loggers]
  keys=root
  
  [handlers]
  keys=file_handler,stream_handler
  
  [formatters]
  keys=formatter
  
  [logger_root]
  level=DEBUG
  handlers=stream_handler
  
  [handler_stream_handler]
  class=StreamHandler
  level=WARNING
  formatter=formatter
  args=(sys.stderr,)
  
  [handler_file_handler]
  class=FileHandler
  level=DEBUG
  formatter=formatter
  args=('empty.log',)
  
  [formatter_formatter]
  format=%(asctime)-s %(name)s %(module)s %(funcName)s %(levelname)-8s %(message)s
  datefmt=%Y-%m-%d %H:%M:%S
  </code></pre>
  
  <p>And here is a basic test python script to uses this ini file:</p>
  
  <pre><code>import logging
  from logging import config
  
  log_config_ini = "log_config.ini"
  logging.config.fileConfig(log_config_ini)
  
  logger = logging.getLogger()
  
  logger.critical('This outputs just to the screen')
  logger.debug("This does not write to either screen (expected) nor file (unexpected)")
  </code></pre>
  
  <p>Note that I can change things like the <code>level</code> for the <code>handler_stream_handler</code> block and everything works as expected, so the configuration file is being read properly. </p>
  
  <p>I've also tried things like <code>logging.config.fileConfig(log_config_ini, disable_existing_loggers = False)</code>, levels, but nothing seems to make a difference, I just get an empty 'empty.log' file.</p>
  
  <p>I'm sure there's just something very basic and silly that will help, but I think I've exhausted google and the Python docs at this point.  Any help would be appreciated, thank you in advance!</p>