[{'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:from scipy.stats import ttest_ind\ndef get_p_values(results, is_reverse=True):\np_values = []\nfor strain, s_data in results.groupby('Strain'):\nif is_reverse:\nfraction_reaction = s_data['Fraction of worms going backwards']\nelse:\nfraction_reaction = s_data['Fraction of worms going forward']\nx = fraction_reaction[s_data['Light']=='OFF'].values\ny = fraction_reaction[s_data['Light']=='ON'].values\n_, p = ttest_ind(x,y, equal_var=False)\np_values.append((strain, p))\np_values = pd.DataFrame(p_values, columns=['strain', 'p_value'])\nreturn p_values\nprint('BACKWARD')\np_values = get_p_values(results_reversal, is_reverse=True)\nprint(p_values)\nprint('FORWARD')\np_values = get_p_values(results_forward, is_reverse=False)\nprint(p_values)"}, {'role': 'assistant', 'content': 'modelling'}]