如何在python脚本中同时使用iperf和grep？

import subprocess

def run_command(command):
    process = subprocess.Popen(command, stdout=subprocess.PIPE, shell=True)
    output, error = process.communicate()
    return output.decode()

# 定义iperf命令和grep命令
iperf_command = "iperf -c <服务器IP地址>"
grep_command = "grep <关键词>"

# 执行iperf命令并获取输出
iperf_output = run_command(iperf_command)

# 将iperf输出作为grep的输入，并执行grep命令
grep_output = run_command(f"echo '{iperf_output}' | {grep_command}")

# 打印grep命令的输出结果
print(grep_output)