[{'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:x_16, y_16 = ecdf(df_postal_code.health_costs_per_head[(df_postal_code['age'] == 16)])\nx_17, y_17 = ecdf(df_postal_code.health_costs_per_head[(df_postal_code['age'] == 17)])\nx_19, y_19 = ecdf(df_postal_code.health_costs_per_head[(df_postal_code['age'] == 19)])\nx_20, y_20 = ecdf(df_postal_code.health_costs_per_head[(df_postal_code['age'] == 20)])"}, {'role': 'assistant', 'content': "['data_preprocessing']"}]