绘制混淆矩阵热图

def solve():
    from sklearn.datasets import load_iris
    from sklearn.tree import DecisionTreeClassifier
    from sklearn.model_selection import cross_val_score
    import numpy as np
    iris = load_iris()
    X = iris.data
    y = iris.target
    best_depth, best_score = 1, 0
    for depth in range(1, 11):
        model = DecisionTreeClassifier(max_depth=depth, random_state=42)
        scores = cross_val_score(model, X, y, cv=5)
        if scores.mean() > best_score:
            best_score = scores.mean()
            best_depth = depth
    print(f'{best_depth},{best_score:.4f}')