title: Custom Logger class and correct line number/function name in log
body: <p>I'd like to wrap Python logger in a custom class to embed some application-specific functionality and hide setup details from developers (setting file output, logging level, etc). To do this, I created a class with the following API:</p>
  
  <pre><code>__init__(log_level, filename)
  debug(msg)
  info(msg)
  warning(msg)
  error(msg)
  </code></pre>
  
  <p>Logger.debug/info/warning/etc calls usually write in the log the function and line number where the log call was made. However, using my custom class, the function and line numbers written to the log file are always the same (correspondent to the debug()/info()/warning()/error() functions inside the custom class). I want it to save the line of application code that logged the msg. Is that possible?</p>
  
  <p>Thanks in advance.</p>