code: def serial_assimilate(self, rootpath):
          
          valid_paths = []
          for (parent, subdirs, files) in os.walk(rootpath):
              valid_paths.extend(self._drone.get_valid_paths((parent, subdirs,
                                                              files)))
          data = []
          count = 0
          total = len(valid_paths)
          for path in valid_paths:
              newdata = self._drone.assimilate(path)
              self._data.append(newdata)
              count += 1
              logger.info('{}/{} ({:.2f}%) done'.format(count, total,
                                                        count / total * 100))
          for d in data:
              self._data.append(json.loads(d, cls=MontyDecoder))
docs: Assimilate the entire subdirectory structure in rootpath serially.