def set_peek(self, dataset, is_multi_byte=False): """Set the peek and blurb text. Get first lines of the main file and set it as the peek.""" main_file = self._get_main_file(dataset) if main_file is None: raise RuntimeError("Unable to find the main file within the 'files_path' folder") # Read first lines of main file with io.open(main_file, encoding='utf-8') as f: data = [] for line in f: if len(data) < _MAX_LINES_HISTORY_PEEK: data.append(line) else: break if not dataset.dataset.purged and data: dataset.peek = json.dumps({"data": data}) dataset.blurb = 'data' else: dataset.peek = 'file does not exist' dataset.blurb = 'file purged from disk'