如何使用os.system()从stdin获取数据

import subprocess

cmd = "echo 'Hello, World!'"
result = subprocess.run(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE, text=True, shell=True)

print("输出：", result.stdout)
print("错误：", result.stderr)

import os

cmd = "echo 'Hello, World!'"
result = os.popen(cmd).read()

print("输出：", result)

import sys

data = sys.stdin.read()
print("从stdin获取的数据：", data)