sklearn.tree.export_graphviz() [source]

Export a decision tree in DOT format.

This function generates a GraphViz representation of the decision tree, which is then written into out_file. Once exported, graphical renderings can be generated using, for example:

$ dot -Tps tree.dot -o tree.ps      (PostScript format)
$ dot -Tpng tree.dot -o tree.png    (PNG format)

The sample counts that are shown are weighted with any sample_weights that might be present.

Read more in the User Guide.


decision_tree : decision tree classifier

The decision tree to be exported to GraphViz.

out_file : file object or string, optional (default=’tree.dot’)

Handle or name of the output file. If None, the result is returned as a string. This will the default from version 0.20.

max_depth : int, optional (default=None)

The maximum depth of the representation. If None, the tree is fully generated.

feature_names : list of strings, optional (default=None)

Names of each of the features.

class_names : list of strings, bool or None, optional (default=None)

Names of each of the target classes in ascending numerical order. Only relevant for classification and not supported for multi-output. If True, shows a symbolic representation of the class name.

label : {‘all’, ‘root’, ‘none’}, optional (default=’all’)

Whether to show informative labels for impurity, etc. Options include ‘all’ to show at every node, ‘root’ to show only at the top root node, or ‘none’ to not show at any node.

filled : bool, optional (default=False)

When set to True, paint nodes to indicate majority class for classification, extremity of values for regression, or purity of node for multi-output.

leaves_parallel : bool, optional (default=False)

When set to True, draw all leaf nodes at the bottom of the tree.

impurity : bool, optional (default=True)

When set to True, show the impurity at each node.

node_ids : bool, optional (default=False)

When set to True, show the ID number on each node.

proportion : bool, optional (default=False)

When set to True, change the display of ‘values’ and/or ‘samples’ to be proportions and percentages respectively.

rotate : bool, optional (default=False)

When set to True, orient tree left to right rather than top-down.

rounded : bool, optional (default=False)

When set to True, draw node boxes with rounded corners and use Helvetica fonts instead of Times-Roman.

special_characters : bool, optional (default=False)

When set to False, ignore special characters for PostScript compatibility.


dot_data : string

String representation of the input tree in GraphViz dot format. Only returned if out_file is None.

New in version 0.18.


>>> from sklearn.datasets import load_iris
>>> from sklearn import tree
>>> clf = tree.DecisionTreeClassifier()
>>> iris = load_iris()
>>> clf = clf.fit(iris.data, iris.target)
>>> tree.export_graphviz(clf,
...     out_file='tree.dot')                

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