Sklearn中决策树的输出会报错

Question

dot_data=tree.export_graphviz(clf,out_file="iris.dot")
graph=pydotplus.graph_from_dot_data(dot_data)
这两行代码出现问题！！
TypeError: object of type 'NoneType' has no len() 错误提示

http://scikit-learn.org/stable/modules/tree.html#classification 代码原来位置

Answer 1

http://blog.csdn.net/lsldd/article/details/41223147