Python子进程将子进程的输出获取到文件和终端？

Question

该脚本会执行多个可执行文件

subprocess.call(cmdArgs,stdout=outf, stderr=errf)

我正在运行一个脚本，当 outf/errf 为 None 或文件描述符（stdout 的不同文件）时， >/stderr）。

有什么方法可以执行每个 exe 以便将 stdout 和 stderr 一起写入文件和终端吗？

Answer 1

call() 函数只是Popen(*args, **kwargs) .wait()。您可以直接调用 Popen 并使用 stdout=PIPE 参数从 p.stdout 读取：

#!/usr/bin/env python
import sys
from subprocess import Popen, PIPE
from threading import Thread


def tee(infile, *files):
    """Print `infile` to `files` in a separate thread."""

    def fanout(infile, *files):
        with infile:
            for line in iter(infile.readline, b""):
                for f in files:
                    f.write(line)

    t = Thread(target=fanout, args=(infile,) + files)
    t.daemon = True
    t.start()
    return t


def teed_call(cmd_args, **kwargs):
    stdout, stderr = [kwargs.pop(s, None) for s in ["stdout", "stderr"]]
    p = Popen(
        cmd_args,
        stdout=PIPE if stdout is not None else None,
        stderr=PIPE if stderr is not None else None,
        **kwargs
    )
    threads = []
    if stdout is not None:
        threads.append(
            tee(p.stdout, stdout, getattr(sys.stdout, "buffer", sys.stdout))
        )
    if stderr is not None:
        threads.append(
            tee(p.stderr, stderr, getattr(sys.stderr, "buffer", sys.stderr))
        )
    for t in threads:
        t.join()  # wait for IO completion
    return p.wait()


outf, errf = open("out.txt", "wb"), open("err.txt", "wb")
assert not teed_call(["cat", __file__], stdout=None, stderr=errf)
assert not teed_call(["echo", "abc"], stdout=outf, stderr=errf, bufsize=0)
assert teed_call(["gcc", "a b"], close_fds=True, stdout=outf, stderr=errf)

Answer 2

你可以使用这样的东西：
https://github.com/waszil/subpiper

在你的回调中你可以做任何你喜欢的事情，记录、写入文件、打印等。还支持非阻塞模式。

from subpiper import subpiper

def my_stdout_callback(line: str):
    print(f'STDOUT: {line}')

def my_stderr_callback(line: str):
    print(f'STDERR: {line}')

my_additional_path_list = [r'c:\important_location']

retcode = subpiper(cmd='echo magic',
                   stdout_callback=my_stdout_callback,
                   stderr_callback=my_stderr_callback,
                   add_path_list=my_additional_path_list)