用python做决策树可视化时,安装了Graphviz,并将其添加到path的环境变量,并且已经安装了pydotplus且import之后,仍然会出现GraphViz’s executables not found问题,可用以下代码解决:
import os
os.environ["PATH"] += os.pathsep + 'C:/Program Files (x86)/Graphviz2.38/bin/'
其中C:/Program Files (x86)/Graphviz2.38/bin/是安装Graphviz的bin所在的路径。
也可以直接在python上安装graphviz
一个例子如下(来自http://scikit-learn.org/stable/modules/tree.html)
from sklearn.datasets import load_iris
from sklearn import tree
import graphviz
iris = load_iris()
clf = tree.DecisionTreeClassifier()
clf = clf.fit(iris.data, iris.target)
dot_data = tree.export_graphviz(clf, out_file=None)
graph = graphviz.Source(dot_data)
graph.render("iris")
dot_data = tree.export_graphviz(clf, out_file=None,
feature_names=iris.feature_names,
class_names=iris.target_names,
filled=True, rounded=True,
special_characters=True)
graph = graphviz.Source(dot_data)
graph