Python의 하위 프로세스에서 실시간 출력을 동시에 캡처하고 기록하려면 어떻게 해야 합니까?

import subprocess
import sys

with open("log.txt", "wb") as f:
    process = subprocess.Popen(your_command, stdout=subprocess.PIPE)
    for c in iter(lambda: process.stdout.read(1), b""):
        sys.stdout.buffer.write(c)
        f.buffer.write(c)

import io
import subprocess
import sys

filename = "log.txt"
with io.open(filename, "wb") as writer, io.open(filename, "rb", 1) as reader:
    process = subprocess.Popen(command, stdout=writer)
    while process.poll() is None:
        sys.stdout.write(reader.read())
        time.sleep(0.5)
    # Read the remaining
    sys.stdout.write(reader.read())