以下是使用并行SSH（pssh）带有输出流的代码示例：

import sys
import subprocess

def execute_command(host, command):
    ssh_command = f'ssh {host} {command}'
    process = subprocess.Popen(ssh_command, shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    stdout, stderr = process.communicate()
    return (stdout.decode(), stderr.decode())

def parallel_ssh(hosts, command):
    processes = []
    for host in hosts:
        ssh_command = f'ssh {host} {command}'
        process = subprocess.Popen(ssh_command, shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
        processes.append(process)

    for process in processes:
        stdout, stderr = process.communicate()
        print(f'Host: {host}')
        print(f'STDOUT:\n{stdout.decode()}')
        print(f'STDERR:\n{stderr.decode()}')
        print('---')

if __name__ == '__main__':
    # 单个主机执行命令
    host = 'example.com'
    command = 'ls -l'
    stdout, stderr = execute_command(host, command)
    print(f'STDOUT:\n{stdout}')
    print(f'STDERR:\n{stderr}')

    # 并行SSH多个主机执行命令
    hosts = ['example1.com', 'example2.com', 'example3.com']
    command = 'ls -l'
    parallel_ssh(hosts, command)

在上述示例中，execute_command函数用于在单个主机上执行命令，并返回stdout和stderr的输出。parallel_ssh函数用于并行SSH多个主机执行相同的命令，并将每个主机的输出流打印出来。