import pandas as pd from sklearn.datasets import load_iris from sklearn.tree import DecisionTreeClassifier from sklearn.model_selection import train_test_split from sklearn.metrics import accuracy_score

加载数据集

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

划分训练集和测试集

X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.3, random_state=42)

定义决策树分类器

clf = DecisionTreeClassifier()

训练模型

clf.fit(X_train, y_train)

预测测试集

y_pred = clf.predict(X_test)

计算准确率

acc = accuracy_score(y_test, y_pred) print('Accuracy:', acc