[{'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:train['date_account_created'] = pd.to_datetime(train['date_account_created'])\ntrain['date_first_booking'] = pd.to_datetime(train['date_first_booking'])\ntrain['timestamp_first_active'] = pd.to_datetime(train['timestamp_first_active'], format='%Y%m%d%H%M%S')\ntrain['timestamp_first_active'] = pd.to_datetime(train['timestamp_first_active']).dt.date\ntest['date_account_created'] = pd.to_datetime(test['date_account_created'])\ntest['timestamp_first_active'] = pd.to_datetime(test['timestamp_first_active'], format='%Y%m%d%H%M%S')\ntest['timestamp_first_active'] = pd.to_datetime(test['timestamp_first_active']).dt.date\n"}, {'role': 'assistant', 'content': "['data_preprocessing']"}]