机器学习-决策树算法
学习内容：载入 scikit-learn 中提供的wine数据集，用决策树分类器实现分类，并可视化分类结果。
引入所要用到的包
from sklearn import datasets
from sklearn import tree
from sklearn.tree import plot_tree
from sklearn.tree import export_text
from sklearn.model_selection import train_test_split
import matplotlib.pyplot as plt
import pandas as pd
载入 scikit-learn 中提供的鸢尾花数据集，用决策树分类器实现分类，用plot_tree()方法进行可视化，并用export_text()方法显示结果。
引入所要用到的包
from sklearn import datasets
from sklearn import tree
from sklearn.tree import plot_tree
from sklearn.tree import export_text
from sklearn.model_selection import train_test_split
import matplotlib.pyplot as plt
import pandas as pd
