[{'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:# lat long location for each device\nevents_latlng = events[[\'device_id\', \'latitude2\',\'longitude2\']].drop_duplicates(\'device_id\', keep=\'first\')\nevents_latlng = events_latlng.set_index(\'device_id\')\nprint(\'Number of devices with some lat long info\',len(events_latlng[\'latitude2\']))\nprint(\'out of that missing longitude: \', sum(events_latlng[\'longitude2\'].isnull())) \nprint(\'out of that missing latitude: \', sum(events_latlng[\'latitude2\'].isnull()))\n\nevents_latlng[\'lng_region\'] = events_latlng[\'longitude2\'].apply(lngregion)\nevents_latlng[\'lat_region\'] = events_latlng[\'latitude2\'].apply(latregion)\n\nprint ("Frequencies longitude region:" \'\\\n\', events_latlng[\'lng_region\'].value_counts())\nprint ("Frequencies latitude region:" \'\\\n\', events_latlng[\'lat_region\'].value_counts())\''}, {'role': 'assistant', 'content': 'data_preprocessing'}]