[{'role': 'system', 'content': "You are an expert in machine learning and your task is to classify code snippets into one of the following categories: ['helper_functions', 'load_data', 'data_exploration', 'data_preprocessing', 'evaluation', 'modelling', 'prediction', 'result_visualization', 'save_results', 'comment_only']."}, {'role': 'user', 'content': "Identify the single most appropriate category to which the provided code belongs. Provide your response as a single category label without any additional information, commentary, or personal opinions.\\nPython Code:# Wrap testing data into pandas' DataFrame.\nlst = list(gen_image_label(test_data_dir))\ntest_df = pd.DataFrame(lst, columns=['label', 'id', 'filename'])\ntest_df = test_df.sort_values(by=['label', 'id'])\ntest_df['label_code'] = test_df.label.map({'cat':0, 'dog':1})\n\ntest_df.head(3)"}, {'role': 'assistant', 'content': 'data_preprocessing'}]