[{'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:train_df = pd.read_pickle('fin-dprep-train.pkl')\ntest_df = pd.read_pickle('fin-dprep-test.pkl')\nfeatures_to_use = pickle.load(open('fin-dprep-flist.pkl', 'rb'))\nmedium_price = pd.read_pickle('fin-medium-price.pkl')\ntrain_df = pd.merge(train_df, medium_price, left_on='listing_id', right_index=True)\ntest_df = pd.merge(test_df, medium_price, left_on='listing_id', right_index=True)"}, {'role': 'assistant', 'content': 'load_data'}]