graphviz 决策树绘图中文乱码解决方法

1、修改graphviz配置文件

<dir>C:\WINDOWS\Fonts</dir>
更改为
<dir>~/.fonts</dir>

2、将决策树dot_data文件保存下来

from sklearn import tree
from sklearn.datasets import load_wine
from sklearn.model_selection import train_test_split
import pandas as pd

wine = load_wine()
Xtrain, Xtest, Ytrain, Ytest = train_test_split(wine.data,wine.target,test_size=0.3)
clf = tree.DecisionTreeClassifier(criterion="entropy")
clf = clf.fit(Xtrain, Ytrain)
score = clf.score(Xtest, Ytest) #返回预测的准确度accuracy

score：0.94444444444444442

feature_name = ['酒精','苹果酸','灰','灰的碱性','镁','总酚','类黄酮','非黄烷类酚类','花青素','颜色强度','色调','od280/od315稀释葡萄酒','脯氨酸']

import graphviz
dot_data = tree.export_graphviz(clf, out_file=".\Tree.dot"
                                ,feature_names = feature_name
                                ,class_names=["琴酒","雪莉","贝尔摩德"]
                                ,filled=True
                                ,rounded=True
                               ) 

生成相应的dot文件如下：

cmd：

切换到相应目录

dot -Tjpg Tree.dot -o tree.jpg

3、dot_data文件格式转换

查看保存在本地的 dot_data.dot 可发现，其默认字体 fontname=helvetica，只需将字体修改为支持的中文字体即可，通过正则表达式实现替换。

import re
# 打开 dot_data.dot，修改 fontname="支持的中文字体"
f = open("./Tree.dot", "r+", encoding="utf-8")
open('./Tree_utf8.dot', 'w', encoding="utf-8").write(re.sub(r'fontname=helvetica', 'fontname="Microsoft YaHei"', f.read()))
f.close()

cmd:

jpg:

dot -Tjpg Tree_utf8.dot -o tree1.jpg

pdf:

dot -Tjpg Tree_utf8.dot -o tree2.pdf