I fails to plot_tree() when I use lightgbm

Question

I fails to plot_tree when I use lightgbm.

I upload traceback as an image, because I cannot download my code from server.

How can I solve this problem?

Answer 1

I've faced a similar issue in the past. If your aim is to investigate which features each tree splits on and which value it splits on you can use an alternative approach:

After instantiating a LightGBM classifier and fitting it to the training data you can then use the trees_to_dataframe() method of the booster of the classifer. This retrieves the data in a relatively easy-to-read format. Even though it doesn't create a plot, the resulting dataframe can be used to investigate the tree in more detail.

Here is an example using the load_breast_cancer dataset from sklearn

from lightgbm import LGBMClassifier
from sklearn.datasets import load_breast_cancer

data = load_breast_cancer()
X, y = data['data'], data['target']
X = pd.DataFrame(X, columns=data['feature_names'])

clf = LGBMClassifier()
clf.fit(X, y)

clf.booster_.trees_to_dataframe()

Output:

	tree_index	node_depth	node_index	left_child	right_child	parent_index	split_feature	split_gain	threshold	decision_type	missing_direction	missing_type	value	weight	count
0	0	1	0-S0	0-S1	0-S3	None	worst_area	3.925050e+02	868.2000	<=	left	None	0.521150	0.000000	569
1	0	2	0-S1	0-S4	0-S2	0-S0	worst_concave_points	6.169360e+01	0.1358	<=	left	None	0.641339	89.298200	382
2	0	3	0-S4	0-S5	0-L5	0-S1	area_error	1.586540e+00	34.7300	<=	left	None	0.672849	78.077500	334
3	0	4	0-S5	0-S8	0-S6	0-S4	worst_texture	7.523920e-01	30.0800	<=	left	None	0.676446	73.402200	314
4	0	5	0-S8	0-L0	0-L9	0-S5	mean_radius	2.842170e-14	13.4950	<=	left	None	0.680533	63.116600	270
...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...
5589	99	4	99-S24	99-L18	99-S27	99-S17	mean_texture	2.184820e-09	15.0450	<=	left	None	-0.100054	0.013308	123
5590	99	5	99-L18	None	None	99-S24	None	NaN	NaN	None	None	None	-0.100125	0.003284	3
5591	99	5	99-S27	99-L25	99-L28	99-S24	worst_radius	6.243950e-10	16.3200	<=	left	None	-0.100031	0.010024	120
5592	99	6	99-L25	None	None	99-S27	None	NaN	NaN	None	None	None	-0.100063	0.003757	9
5593	99	6	99-L28	None	None	99-S27	None	NaN	NaN	None	None	None	-0.100012	0.006267	111