[{'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:#X_Test = df_test.loc[:, [\'State\', \'Country\', \'Date\']]\nX_Test = df_test.copy()\n\nX_Test[\'State\'].fillna(EMPTY_VAL, inplace=True)\nX_Test[\'State\'] = X_Test.loc[:, [\'State\', \'Country\']].apply(lambda x : fillState(x[\'State\'], x[\'Country\']), axis=1)\n\nX_Test.loc[:, \'Date\'] = X_Test.Date.dt.strftime("%m%d")\nX_Test["Date"]  = X_Test["Date"].astype(int)\n\nX_Test.head()\''}, {'role': 'assistant', 'content': 'data_preprocessing'}]