如何使用Python将WEKA分类器错误保存到arff文件？

import weka.core.serialization as serialization
import weka.core.converters as converters
import weka.classifiers as classifiers
import weka.core.dataset as dataset

classifier = serialization.read("path/to/classifier.model")

data = converters.load_any_file("path/to/data.arff")

error_data = dataset.Instances.copy_instances(data)
error_data.delete()

for i in range(data.num_instances):
    instance = data.get_instance(i)
    true_class = instance.get_class_value()
    predicted_class = classifier.classify_instance(instance)
    if true_class != predicted_class:
        error_data.add_instance(instance)

converters.ArffSaver().save_file("path/to/error_data.arff", error_data)