CART决策树运行到最后产生IndexError: list index out of range错误，跪求大神指点！

[阿黄king]

from IPython.display import Image  
dot_data = tree.export_graphviz(clf, out_file=None, 
                         feature_names=feature.columns.tolist(),
                         class_names=target_names,
                         filled=True, rounded=True,  
                         special_characters=True,node_ids=True,rotate=True,label='all')   
graph = pydotplus.graph_from_dot_data(dot_data.replace('\n','').replace('helvetica', '"Microsoft YaHei"'))  
Image(graph.create_png())

这是我最后的一个代码块，然后运行之后就报错了，错误如下

IndexError                                Traceback (most recent call last)
<ipython-input-225-760bece3996a> in <module>
      4                          class_names=target_names,
      5                          filled=True, rounded=True,
----> 6                          special_characters=True,node_ids=True,rotate=True,label='all')   
      7 graph = pydotplus.graph_from_dot_data(dot_data.replace('\n','').replace('helvetica', '"Microsoft YaHei"'))
      8 Image(graph.create_png())

~\Anaconda3\lib\site-packages\sklearn\tree\export.py in export_graphviz(decision_tree, out_file, max_depth, feature_names, class_names, label, filled, leaves_parallel, impurity, node_ids, proportion, rotate, rounded, special_characters, precision)
    457 
    458         # Now recurse the tree and add node & edge attributes
--> 459         recurse(decision_tree.tree_, 0, criterion=decision_tree.criterion)
    460 
    461         # If required, draw leaf nodes at same depth as each other

~\Anaconda3\lib\site-packages\sklearn\tree\export.py in recurse(tree, node_id, criterion, parent, depth)
    377             if left_child != _tree.TREE_LEAF:
    378                 recurse(tree, left_child, criterion=criterion, parent=node_id,
--> 379                         depth=depth + 1)
    380                 recurse(tree, right_child, criterion=criterion, parent=node_id,
    381                         depth=depth + 1)

~\Anaconda3\lib\site-packages\sklearn\tree\export.py in recurse(tree, node_id, criterion, parent, depth)
    334             out_file.write('%d [label=%s'
    335                            % (node_id,
--> 336                               node_to_str(tree, node_id, criterion)))
    337 
    338             if filled:

~\Anaconda3\lib\site-packages\sklearn\tree\export.py in node_to_str(tree, node_id, criterion)
    299                 node_string += 'class = '
    300             if class_names is not True:
--> 301                 class_name = class_names[np.argmax(value)]
    302             else:
    303                 class_name = "y%s%s%s" % (characters[1],

IndexError: list index out of range

试了好多种办法都得不到解决，有没有大神指点！急