绘制决策树,graphvizm pydotplus

Question

我正在关注scikit文档的决策树教程.我有,pydotplus 2.0.2但它告诉我它没有write方法 - 错误如下.我现在一直苦苦挣扎,有什么想法,好吗？非常感谢!

from sklearn import tree
from sklearn.datasets import load_iris

iris = load_iris()
clf = tree.DecisionTreeClassifier()
clf = clf.fit(iris.data, iris.target)

from IPython.display import Image

dot_data = tree.export_graphviz(clf, out_file=None)
import pydotplus

graph = pydotplus.graphviz.graph_from_dot_data(dot_data)

Image(graph.create_png())

而我的错误是

    /Users/air/anaconda/bin/python /Users/air/PycharmProjects/kiwi/hemr.py
Traceback (most recent call last):
  File "/Users/air/PycharmProjects/kiwi/hemr.py", line 10, in <module>
    dot_data = tree.export_graphviz(clf, out_file=None)
  File "/Users/air/anaconda/lib/python2.7/site-packages/sklearn/tree/export.py", line 375, in export_graphviz
    out_file.write('digraph Tree {\n')
AttributeError: 'NoneType' object has no attribute 'write'

Process finished with exit code 1

-----更新-----

使用修复程序out_file,它会引发另一个错误:

 Traceback (most recent call last):
  File "/Users/air/PycharmProjects/kiwi/hemr.py", line 13, in <module>
    graph = pydotplus.graphviz.graph_from_dot_data(dot_data)
  File "/Users/air/anaconda/lib/python2.7/site-packages/pydotplus/graphviz.py", line 302, in graph_from_dot_data
    return parser.parse_dot_data(data)
  File "/Users/air/anaconda/lib/python2.7/site-packages/pydotplus/parser.py", line 548, in parse_dot_data
    if data.startswith(codecs.BOM_UTF8):
AttributeError: 'NoneType' object has no attribute 'startswith'

---- 更新2 -----

另外,下面我自己的答案解决了另一个问题

Answer 1

问题是你要设置参数out_fileNone NoneNone Nonestring stringstring`没有'write'方法.

因此,请执行以下操作:

dot_data = tree.export_graphviz(clf)
graph = pydotplus.graphviz.graph_from_dot_data(dot_data)