list object has no attribute write_png

pydot, graphviz 사용시 아래와 같은 에러가 발생하는 경우

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

>>> import pydot,StringIO
>>> 
>>> dot_data = StringIO.StringIO() 
>>> 
>>> tree.export_graphviz(clf, out_file=dot_data,feature_names=['age','sex','1st_class','2nd_class','3rd_class']) 
>>> 
>>> graph = pydot.graph_from_dot_data(dot_data.getvalue()) 
>>> 
>>> graph.write_png('titanic.png') 
>>> 
>>> from IPython.core.display import Image 
>>> 
>>> Image(filename='titanic.png')
 
------------------------------------------------------------
AttributeError             Traceback (most recent call last)
<ipython-input-17-0effc3f1d020> in <module>()
      3 tree.export_graphviz(clf, out_file=dot_data,feature_names=['age','sex','1st_class','2nd_class','3rd_class'])
      4 graph = pydot.graph_from_dot_data(dot_data.getvalue())
----> 5 graph.write_png('titanic.png')
      6 from IPython.core.display import Image
      7 Image(filename='titanic.png')
 
AttributeError: 'list' object has no attribute 'write_png'

pydot 대신 pydotplus 를 설치하면 사용하면 된다.

pip install pydotplus

>>> import pydotplus,StringIO
>>> dot_data = StringIO.StringIO() 
>>> tree.export_graphviz(clf, out_file=dot_data,feature_names=['age','sex','1st_class','2nd_class','3rd_class']) 
>>> graph = pydotplus.graph_from_dot_data(dot_data.getvalue()) 
>>> graph.write_png('titanic.png') 
>>> from IPython.core.display import Image 
>>> Image(filename='titanic.png')