LGBM 模型结果 图形展示

一、LGBM 模型结果 图形展示：

1、模型训练

train_x = train[feas_x]
train_y= train['target'].astype(int).copy()
test_x, test_y = test[feas_x], test['target']

lgb_clf = lgb.LGBMClassifier(objective='binary',metric='auc',num_leaves=20,max_depth=2,learning_rate=0.06,seed=27,
colsample_bytree=0.7,subsample=0.7,n_estimators=500)
lgb_model = lgb_clf.fit(train_x, train_y, eval_set=[(test_x, test_y)], early_stopping_rounds=200)

2、打印树让其用以下图片方式展示

2.1 下载 Graphvizjar

该网址（Download | Graphviz ）下载自己需要的Graphvizjar 版本 ,本示例用的是 graphviz-3.0.0(64.bit)

2.2 安装 graphviz

2.3 调用graphviz （D:\\Graphviz\\ 为Graphviz 安装路径） 

import os
os.environ["PATH"] += os.pathsep + 'D:\\Graphviz\\bin\\'

2.4 用graphviz  画图，tree_index 为打印第几棵树
lgb.create_tree_digraph(lgb_model, tree_index=8,show_info=['split_gain','leaf_count',])

其中 show_info 参数 可参考：lightgbm.create_tree_digraph — LightGBM 3.3.2.99 documentation