python - 从 sklearn.model_selection.GridSearchCV 获取 keyerror

Question

我正在尝试使用 GridSearchCV 实现决策树分类器。实现后，我尝试访问 cv_results_.mean_train_score 但出现关键错误。

    tuned_parameters = [{'max_depth': [1, 5, 10, 25, 50, 75, 100, 150, 250, 500, 750, 1000], 
                         'min_samples_split' : [5, 10, 25, 50, 75, 150, 250, 500]}] 
    cv_timeSeries = TimeSeriesSplit(n_splits=4).split(X_train)
    base_estimator = DecisionTreeClassifier(class_weight='balanced') 
    gsearch_cv = GridSearchCV(estimator=base_estimator, 
                              param_grid=tuned_parameters, 
                              cv=cv_timeSeries, 
                              scoring='roc_auc', 
                              n_jobs=-1)
    gsearch_cv.fit(X_train, y_train)

当我尝试访问 gsearch_cv 的所有键时，我无法找到字典键 mean_train_score。

Answer 1

在GridSearchCV中添加参数跟随参数

GridSearchCV(return_train_score=True)