[{'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:test_merged['StateHoliday']=test_merged['StateHoliday'].map({'0':0,'a':1})\ntest_merged['StateHoliday']=test_merged['StateHoliday'].astype(int)\n\ntest_merged['StoreType']=test_merged['StoreType'].map({'a':0,'b':1,'c':2,'d':3})\ntest_merged['StoreType']=test_merged['StoreType'].astype(int)\n\ntest_merged['Assortment']=test_merged['Assortment'].map({'a':0,'b':1,'c':2})\ntest_merged['Assortment']=test_merged['Assortment'].astype(int)\n\ntest_merged['PromoInterval']=test_merged['PromoInterval'].map({'Jan,Apr,Jul,Oct':0,'Feb,May,Aug,Nov':1,'Mar,Jun,Sept,Dec':2})\ntest_merged['PromoInterval']=test_merged['PromoInterval'].astype(int)"}, {'role': 'assistant', 'content': 'data_preprocessing'}]