[{'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:scaler = StandardScaler()\nx1 = scaler.fit_transform(x1)\nx2 = scaler.transform(x2)\nmodel = multiclass.OneVsRestClassifier(ensemble.RandomForestClassifier(max_depth = 7, n_estimators=1000, random_state=33))\n# model = multiclass.OneVsRestClassifier(ensemble.ExtraTreesClassifier(n_jobs=-1, n_estimators=100, random_state=33))\n\n# param_dist = {'objective': 'binary:logistic', 'max_depth': 1, 'n_estimators':1000, 'num_round':1000, 'eval_metric': 'logloss'}\n# model = multiclass.OneVsRestClassifier(xgb.XGBClassifier(**param_dist))\n\nmodel.fit(x1, y1)\nprint('log_loss', metrics.log_loss(y2, model.predict_proba(x2)))"}, {'role': 'assistant', 'content': "['data_preprocessing']"}]