[{'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:def calculateFlightTime(dataframe):\nflight_times = [];\nindex_of_releases = ((dataframe[dataframe['action']=='RELEASED']).index.tolist());\nrange_of_events = list(range(index_of_releases[0], index_of_releases[-1]));\nindex_of_presses = list(set(range_of_events).difference(index_of_releases));\nfirst_press = index_of_presses[0];\nwhile (index_of_presses[0]<index_of_releases[0]):\ndel index_of_releases[0];\nwhile(len(index_of_presses)>0):\nflight_times.append((float(dataframe['timestamp'].iloc[index_of_presses[0]]) - float(dataframe['timestamp'].iloc[index_of_releases[0]])));\ndel index_of_releases[0]\ndel index_of_presses[0]\nreturn flight_times;"}, {'role': 'assistant', 'content': "['data_preprocessing']"}]