code: def set_file_logger(path, log_level=logging.DEBUG, format_string=None, logger_name='smc'):
      
      if format_string is None: 
          format_string = LOG_FORMAT
      
      log = logging.getLogger(logger_name)
      log.setLevel(log_level)
  
      # create file handler and set level
      ch = logging.FileHandler(path)
      ch.setLevel(log_level)
      # create formatter
      formatter = logging.Formatter(format_string)
      # add formatter to ch
      ch.setFormatter(formatter)
      # add ch to logger
      log.addHandler(ch)
docs: Convenience function to quickly configure any level of logging
      to a file.
  
      :param int log_level: A log level as specified in the `logging` module
      :param str format_string: Optional format string as specified in the 
          `logging` module
      :param str path: Path to the log file.  The file will be created
          if it doesn't already exist.