[{'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:tech_list = [\'AAPL\',\'GOOG\',\'MSFT\',\'AMZN\']\nend = datetime.now()\nstart = datetime(end.year - 1,end.month,end.day)\nfor stock in tech_list:\nglobals()[stock] = DataReader(stock,\'yahoo\',start,end)\nglobals()[stock]["Date"] = globals()[stock].index.date\nglobals()[stock].set_index("Date", drop=True, inplace=True)'}, {'role': 'assistant', 'content': 'load_data'}]