[{'role': 'system', 'content': "You are an expert in machine learning and your task is to classify the code snippets into categories from the provided list of categories. List of categories: ['helper_functions', 'load_data', 'data_exploration', 'data_preprocessing', 'evaluation', 'modelling', 'prediction', 'result_visualization', 'save_results', 'comment_only']"}, {'role': 'user', 'content': "Identify to which category the provided code belongs and assign the code snippet to at least 1 but up to 5 categories based on the probabilities, ignore if the probability of the category is negligible. Strictly provide your response as a list. Avoid providing any additional information, commentary, or personal opinions.\\nPython Code:def run_to_stackdf(run):\ndf_testpreds = pd.DataFrame(run[2].mean(axis=0))\ndf_testpreds.columns = ['level']\ndf_testpreds['listing_id'] = cv_test[0].listing_id\ndf_allpreds = pd.concat([run[1][['level', 'listing_id']], df_testpreds])\ndf_allpreds.sort_values('listing_id', inplace=True)\ndf_allpreds.set_index('listing_id', inplace=True)\ndf_fold = []\nfor f in range(run[2].shape[0]):\ndf_fold.append(pd.DataFrame(run[2][f]))\ndf_fold[-1]['listing_id'] = test_df.listing_id\ndf_fold[-1].sort_values('listing_id', inplace=True)\ndf_fold[-1].set_index('listing_id', inplace=True)\nreturn (df_allpreds, df_fold)"}, {'role': 'assistant', 'content': "['data_preprocessing']"}]