[{'role': 'system', 'content': "You are an expert in machine learning and your task is to classify the code snippets into categories from the provided list of categories. List of categories: ['helper_functions', 'load_data', 'data_exploration', 'data_preprocessing', 'evaluation', 'modelling', 'prediction', 'result_visualization', 'save_results', 'comment_only']"}, {'role': 'user', 'content': "Identify to which category the provided code belongs and assign the code snippet to at least 1 but up to 5 categories based on the probabilities, ignore if the probability of the category is negligible. Strictly provide your response as a list. Avoid providing any additional information, commentary, or personal opinions.\\nPython Code:test_df = pd.read_csv('../input/act_test.csv')\ntest_df['activity_category'] = test_df['activity_category'].astype('category').cat.codes\ncolumns = ['char_'+str(i) for i in range(1,11)]\ntest_df[columns] = test_df[columns].apply(lambda x: x.astype('category').cat.codes)\ntest_df['date'] = pd.to_datetime(test_df['date'])\ntest_df['day'] = test_df['date'].apply(lambda x:x.day)\ntest_df['year'] = test_df['date'].apply(lambda x:x.year)\ntest_df['month'] = test_df['date'].apply(lambda x:x.month)\ntest_df = test_df.drop(['date'],axis = 1)"}, {'role': 'assistant', 'content': "['data_preprocessing']"}]