[{'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:# date_first_booking\n\ndef get_year(date):\n    if date == date: \n        return int(str(date)[:4])\n    return date\n\ndef get_month(date):\n    if date == date: \n        return int(str(date)[5:7])\n    return date\n\n# Create Year and Month columns\nairbnb_df['Year']  = airbnb_df['date_first_booking'].apply(get_year)\nairbnb_df['Month'] = airbnb_df['date_first_booking'].apply(get_month)\n\ntest_df['Year']  = test_df['date_first_booking'].apply(get_year)\ntest_df['Month'] = test_df['date_first_booking'].apply(get_month)\n\n# fill NaN\nairbnb_df['Year'].fillna(airbnb_df['Year'].median(), inplace=True)\nairbnb_df['Month'].fillna(airbnb_df['Month'].median(), inplace=True)\n\ntest_df['Year'].fillna(test_df['Year'].median(), inplace=True)\ntest_df['Month'].fillna(test_df['Month'].median(), inplace=True)\n\n# convert type to integer\nairbnb_df[['Year', 'Month']] = airbnb_df[['Year', 'Month']].astype(int)\ntest_df[['Year', 'Month']]   = test_df[['Year', 'Month']].astype(int)\n"}, {'role': 'assistant', 'content': "['data_preprocessing']"}]