code: def _get_filename(self):
          
          if self._fname is None:
              timestamp = datetime.datetime.now().strftime("%Y%m%d-%H%M%S")
              fname = "%s-%s.log" % (timestamp, abs(id(self)))
              self._fname = os.path.join(self.file_path, fname)
          return self._fname
docs: Return a unique file name.