(from python machine learning)

Finished everything but was told to chose the hyperparameters from a (predetermined) set of candidates instead of just using a single hyperparameter[enter image description here][1] but i dont know what this means and his explanation was confusing. I really need help since I've been struggling for days trying to figure out how to do this. ( i attached some of the code..

2) Choose hyperparameter max_depth using the validation set method.

[11]: from sklearn.model_selection import cross_val_score

3) Choose hyperparameter max_depth using 4-fold cross validation.

[13]: from sklearn.model_selection import KFold

[14]: kf=KF