graphviz 安装使用

官网：

https://www.graphviz.org/

下载地址：

windows:  https://www2.graphviz.org/Packages/stable/windows/10/cmake/Release/x64/

案例：

from sklearn.datasets import load_iris
from sklearn.tree import DecisionTreeClassifier
from sklearn.tree import export_graphviz

# 'target_names': array(['setosa', 'versicolor', 'virginica'], dtype='<U10')
# 'feature_names': ['sepal length (cm)', 'sepal width (cm)', 'petal length (cm)', 'petal width (cm)']
iris = load_iris()
x = iris.data[:, 2:]
y = iris.target

clf = DecisionTreeClassifier(max_depth=2)
clf.fit(x, y)

export_graphviz(clf, out_file="tree.dot",
                feature_names=iris.feature_names[2:],
                class_names=iris.target_names,
                rounded=True,
                filled=True)

# dot -Tpng tree.dot -o tree.png