[{'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:# Split Train Set & Test Set\nfrom sklearn.model_selection import train_test_split\n\nY = X_sm['loss']\nX = X_sm.drop(columns = 'loss')\n\nX_train, X_test, Y_train, Y_test = train_test_split( X, Y, test_size = 0.2, random_state = 1234, stratify = Y_sm)\nprint('training set = {} records, test set= {} records'.format(X_train.shape[0],X_test.shape[0]))"}, {'role': 'assistant', 'content': 'data_preprocessing'}]