[{'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:def bar_chart(feature):<br>    low = train[train['interest_level']=='low'][feature].value_counts() # survived     <br>    medium = train[train['interest_level']=='medium'][feature].value_counts()<br>    high = train[train['interest_level']=='high'][feature].value_counts()<br>    df = pd.DataFrame([low, medium, high])<br>    df.index = ['low','medium','high']<br>    df.plot(kind='bar',stacked=True, figsize=(10,5))"}, {'role': 'assistant', 'content': 'result_visualization'}]