将决策树直接转换为png [重复]

Question

我正在尝试生成一个我想使用点来可视化的决策树。生成的点文件应转换为 png。

虽然我可以使用类似的东西在 dos 中完成最后一个转换步骤

export_graphviz(dectree, out_file="graph.dot")

后跟一个 DOS 命令

dot -Tps graph.dot -o outfile.ps

直接在python中做所有这些都不起作用并产生错误

AttributeError: 'list' object has no attribute 'write_png'

这是我试过的程序代码：

from sklearn import tree  
import pydot
import StringIO

# Define training and target set for the classifier
train = [[1,2,3],[2,5,1],[2,1,7]]
target = [10,20,30]

# Initialize Classifier. Random values are initialized with always the same random seed of value 0 
# (allows reproducible results)
dectree = tree.DecisionTreeClassifier(random_state=0)
dectree.fit(train, target)

# Test classifier with other, unknown feature vector
test = [2,2,3]
predicted = dectree.predict(test)

dotfile = StringIO.StringIO()
tree.export_graphviz(dectree, out_file=dotfile)
graph=pydot.graph_from_dot_data(dotfile.getvalue())
graph.write_png("dtree.png")

我错过了什么？

Answer 1

我最终使用了 pydotplus：

from sklearn import tree  
import pydotplus
import StringIO

# Define training and target set for the classifier
train = [[1,2,3],[2,5,1],[2,1,7]]
target = [10,20,30]

# Initialize Classifier. Random values are initialized with always the same random seed of value 0 
# (allows reproducible results)
dectree = tree.DecisionTreeClassifier(random_state=0)
dectree.fit(train, target)

# Test classifier with other, unknown feature vector
test = [2,2,3]
predicted = dectree.predict(test)

dotfile = StringIO.StringIO()
tree.export_graphviz(dectree, out_file=dotfile)
graph=pydotplus.graph_from_dot_data(dotfile.getvalue())
graph.write_png("dtree.png")

编辑：感谢您的评论，要让它在 pydot 中运行，我必须写：

(graph,)=pydot.graph_from_dot_data(dotfile.getvalue())