交叉验证python代码

以下是一些基本的交叉验证Python代码：

使用Python的sklearn模块执行5倍交叉验证：

from sklearn.datasets import load_iris
from sklearn.model_selection import cross_val_score
from sklearn.tree import DecisionTreeClassifier

iris = load_iris()
X = iris.data
y = iris.target

clf = DecisionTreeClassifier(random_state=0)
scores = cross_val_score(clf, X, y, cv=5)
print(scores)

使用Python的sklearn模块执行留一法交叉验证：

from sklearn.datasets import load_iris
from sklearn.model_selection import LeaveOneOut
from sklearn.tree import DecisionTreeClassifier

iris = load_iris()
X = iris.data
y = iris.target

clf = DecisionTreeClassifier(random_state=0)
loo = LeaveOneOut()
scores = cross_val_score(clf, X, y, cv=loo)
print(scores)

使用Python的sklearn模块执行k折交叉验证：

from sklearn.datasets import load_iris
from sklearn.model_selection import KFold
from sklearn.tree import DecisionTreeClassifier

iris = load_iris()
X = iris.data
y = iris.target

clf = DecisionTreeClassifier(random_state=0)
kf = KFold(n_splits=5)
scores = cross_val_score(clf, X, y, cv=kf)
print(scores)