如何在python中给出分层k倍抽样的测试大小？

import random
from collections import Counter

def stratified_kfold_sampling(data, k):
    # 计算每个层级的样本数量
    counts = Counter(data)
    sizes = {key: int(count * k) for key, count in counts.items()}
    
    # 初始化抽样结果
    samples = {key: [] for key in counts.keys()}
    
    # 对每个层级进行抽样
    for key in counts.keys():
        layer_data = [item for item in data if item == key]
        samples[key] = random.sample(layer_data, sizes[key])
    
    # 将抽样结果合并为一个列表
    result = [item for sublist in samples.values() for item in sublist]
    
    return result

data = [1, 1, 1, 2, 2, 2, 3, 3, 3, 3]  # 样本数据，假设有3个层级
k = 0.5  # k倍抽样，抽样比例为50%

sampled_data = stratified_kfold_sampling(data, k)
print(sampled_data)