[{'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:# concat Country/Region and Province/State\ndef func(x):\n    try:\n        x_new = x[\'Country_Region\'] + "/" + x[\'Province_State\']\n    except:\n        x_new = x[\'Country_Region\']\n    return x_new\n        \ndf_traintest[\'place_id\'] = df_traintest.apply(lambda x: func(x), axis=1)\ndf_traintest.head()\''}, {'role': 'assistant', 'content': 'data_preprocessing'}]