[{'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:X_test = testdf.copy()\n\nX_test['people_pb'] = X_test.population/X_test.total_bedrooms\nX_test['people_ph'] = X_test.population/X_test.households\nX_test['income_pr'] = X_test.median_income/X_test.total_rooms\n\nX_test = X_test.filter(['median_age','total_rooms', 'total_bedrooms', 'population', 'households', 'median_income', 'city_price', 'people_pb','people_ph', 'income_pr'], axis = 1)\nX_test.describe()"}, {'role': 'assistant', 'content': "['data_preprocessing']"}]