[{'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:XtrainHouses = trainHouses.drop(["Id", "median_house_value"], axis="columns")\nXtrainHousesB = trainHouses.drop(["Id", "median_house_value", "median_age", "total_rooms", "total_bedrooms", "population", "households"], axis="columns")\nYtrainHouses = trainHouses["median_house_value"]\n\nXtestHouses = testHouses.drop("Id", axis="columns")\nXtestHousesB = testHouses.drop(["Id", "median_age", "total_rooms", "total_bedrooms", "population", "households"], axis="columns")'}, {'role': 'assistant', 'content': 'data_preprocessing'}]