[{'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:%%time\nlast_activity = np.max(events_test.time.values)\nuser_achived_score_test = np.array([])\nuser_discovered_test = np.array([])\nuser_passed_test = np.array([])\nuser_not_doing_anything_test = np.array([])\nfor user in events_test.groupby('user_id').sum().index:\nuser_achived_score_test = np.append(user_achived_score_test, np.sum(events_test[events_test.user_id==user][events_test.action=='passed'].step_cost.values))\nuser_passed_test = np.append(user_passed_test, events_test[events_test.user_id==user][events_test.action=='passed'].shape[0])\nuser_discovered_test = np.append(user_discovered_test, events_test[events_test.user_id==user][events_test.action=='discovered'].shape[0])\nlast_user_activity = np.max(events_test[events_test.user_id==user]['time'])\nuser_not_doing_anything_test = np.append(user_not_doing_anything_test, last_activity - last_user_activity)\nif user % 1000 < 3:\nprint('user ' + str(user) + ' finished')"}, {'role': 'assistant', 'content': "['data_preprocessing']"}]