分类决策树的核心思想就是在一个数据集中找到一个最优特征，然后从这个特征的选值中找一个最优候选值，根据这个最优候选值将数据集分为两个子数据集，然后递归上述操作，直到满足指定条件为止。附代码(The core idea of a classified decision tree is to find an optimal feature in a data set, and then find an optimal candidate value from the selected value of this feature, and divide the data set into two sub data sets according to the optimal candidate value, and then recurse the above operation until the specified condition is satisfied)