from sklearn.ensemble import RandomForestClassifier
from sklearn.model_selection import train_test_split
from sklearn.metrics import accuracy_score
from sklearn.datasets import load_iris
import numpy as np
iris = load_iris()
X = iris["data"]
y = iris["target"]
np.random.seed(0)
X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.2, random_state=0)
clf = RandomForestClassifier()
clf.fit(X_train, y_train)
print('训练集准确率:', accuracy_score(y_train, clf.predict(X_train)))
print('测试集准确率:', accuracy_score(y_test, clf.predict(X_test)))