[{'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:mixed_data1=mixed_data.copy()\nfor col in mixed_data1.columns:\nif mixed_data1[col].dtype == 'object':\naux=pd.get_dummies(mixed_data1[col])\nnames_aux=[]\nfor i,name in enumerate(aux.columns):\nnames_aux= names_aux+[col+'_'+name]\naux.columns=names_aux\nmixed_data1=mixed_data1.drop(col,1)\nmixed_data1=mixed_data1.join(aux)"}, {'role': 'assistant', 'content': 'data_preprocessing'}]