[{'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:yemen_data.shape\nprob_cols = ['Q31.Choice1','Q31.Choice2','Q31.Choice3','Q31.Choice4','Q31.Choice5',\n'Q32.Choice1','Q32.Choice2','Q32.Choice3','Q32.Choice4','Q32.Choice5','Q32.Choice6']\nfor element in prob_cols:\ndel yemen_data[str(element)]"}, {'role': 'assistant', 'content': 'data_preprocessing'}]