[{'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:import pandas as pd\nimport os\nfile_dir = r'C:\\Users\\Noah\\Desktop\\python\\census\\data\\\\'\ndf_cen = pd.read_csv('CC-EST2014-ALLDATA.csv',encoding='latin-1', dtype={'STATE':str, 'COUNTY':str})\nfor filename in os.listdir(file_dir):\ntmp = pd.read_csv(file_dir+filename,encoding='latin-1', dtype={'STATE':str, 'COUNTY':str})\ndf_cen.append(tmp)"}, {'role': 'assistant', 'content': 'load_data'}]