[{'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:df_correlation=df_train_store[['Store', 'DayOfWeek', 'Sales', 'Customers', 'Open', 'Promo',\n        'SchoolHoliday',\n       'CompetitionDistance', 'CompetitionOpenSinceMonth',\n       'CompetitionOpenSinceYear', 'Promo2', 'Promo2SinceWeek',\n       'Promo2SinceYear', 'SalesperCustomer', 'Month', 'Year',\n       'Day', 'StateHoliday_cat', 'Assortment_cat', 'StoreType_cat',\n       'PromoInterval_cat']]"}, {'role': 'assistant', 'content': 'helper_functions'}]