# 实例化模型
# booster=\'gbtree\' 用CART回归树作为基分类器
# objective=\'binary:logistic\' 用二分类逻辑回归损失函数
xgb = XGBClassifier(booster=\'gbtree\',objective=\'binary:logistic\',
eval_metric = \"error\",max_depth=5,
subsample=0.8, colsample_bytree=0.8,
min_child_weight= 5, learning_rate= 0.1,
n_jobs= -1 , verbosity=2,random_state=0,
n_estimators=10,)