[{'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:AOM = em.read_csv_metadata(path_to_csv_dir + '_aom_cleaned.csv', key = csv_headers.AOM_INDEX)\nWHED = em.read_csv_metadata(path_to_csv_dir + '_whed_cleaned.csv', key = csv_headers.WHED_INDEX)\nsample_WHED, sample_AOM = em.down_sample(WHED, AOM, size=4000, y_param=3)\nprint(len(sample_WHED))\nprint(len(sample_AOM))"}, {'role': 'assistant', 'content': 'load_data'}]