如何获取Python.subprocess中的丢包值

import subprocess

def get_packet_loss(target):
    # 构造ping命令
    ping_command = ["ping", "-c", "5", target]  # 发送5个ICMP请求

    try:
        # 执行ping命令
        result = subprocess.run(ping_command, capture_output=True, text=True, check=True)

        # 解析ping命令的输出
        output = result.stdout.split('\n')
        loss_line = output[-2]  # 获取丢包行
        packet_loss = float(loss_line.split('%')[0].split(' ')[-1])  # 提取丢包率
        return packet_loss

    except subprocess.CalledProcessError:
        print("执行ping命令时出现错误")
        return None

# 示例使用
target_host = "www.example.com"
packet_loss = get_packet_loss(target_host)
if packet_loss is not None:
    print("丢包率: {:.2f}%".format(packet_loss))
else:
    print("无法获取丢包率")