Python在Popen.stdout.readline上设置超时

import subprocess
import select
import time

def read_line_with_timeout(process, timeout):
    start_time = time.time()
    while True:
        # 检查子进程的标准输出是否有数据可读取
        ready, _, _ = select.select([process.stdout], [], [], timeout)

        if ready:
            # 读取数据
            line = process.stdout.readline()
            if line:
                return line.decode().strip()
            else:
                # 子进程结束，没有更多数据可读取
                break

        if time.time() - start_time >= timeout:
            # 超时
            break

    # 超时或子进程结束时返回None
    return None

# 示例用法
cmd = ['command', 'arg1', 'arg2']
process = subprocess.Popen(cmd, stdout=subprocess.PIPE)

line = read_line_with_timeout(process, timeout=5)
if line:
    print(line)
else:
    print("读取超时或子进程结束")

# 关闭子进程
process.terminate()