code: def _create_import_log(items):
      
      log = []
  
      for item in items:
          if isinstance(item, MetadataFile):
              log.append(
                  "Metadata file '%s' successfully imported." % item.filename
              )
          elif isinstance(item, EbookFile):
              log.append(
                  "Ebook file '%s' successfully imported." % item.filename
              )
          elif isinstance(item, DataPair):
              meta = item.metadata_file.filename
              data = item.ebook_file.filename
              log.extend([
                  "Metadata and data files paired to epub. import request:",
                  "\tMetadata file '%s' successfully imported." % meta,
                  "\tEbook file '%s' successfully imported." % data
              ])
  
      return log
docs: Used to create log with successfully imported data.