grid_search.fit(X_train,y_train)
E:\anaconda3.7\lib\site-packages\sklearn\model_selection_split.py:1978: FutureWarning: The default value of cv will change from 3 to 5 in version 0.22. Specify it explicitly to silence this warning.
warnings.warn(CV_WARNING, FutureWarning)
老师,我在运行上述代码时遇到了warning,但是不理解这段warning什么意思 ?该怎么处理?