• “ls：cannot access /home/non：No such file or directory”* 是ls命令生成的，这里不是bash。

如果你想使用异常处理来处理不存在的文件，那么使用subprocess.check_output()：

#!/usr/bin/env python
from subprocess import check_output, STDOUT, CalledProcessError

try:
    output = check_output(['ls', 'nonexistent'], stderr=STDOUT)
except CalledProcessError as exc:
    print(exc.output)
else:
    assert 0

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输出

ls: cannot access nonexistent: No such file or directory

型

您可以将stderr重定向到文件对象：

from subprocess import PIPE, CalledProcessError, check_call, Popen

with open("log.txt", "w") as f:
    try:
        check_call(["ls", "/home/non"], stderr=f)
        df = Popen(["ls", "/home/non"], stdout=PIPE)
        output, err = df.communicate()
    except CalledProcessError as e:
        print(e)
        exit(1)

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输出到log.txt：

ls: cannot access /home/non: No such file or directory

型
如果您希望在except中显示消息：

try:
    check_call(["ls", "/home/non"])
    df = Popen(["ls", "/home/non"], stdout=PIPE)
    output, err = df.communicate()
except CalledProcessError as e:
    print(e.message)

型
对于python 2.6，e.message将无法工作。您可以使用python 2.7的check_output的类似版本，它将与python 2.6一起工作：

from subprocess import PIPE, CalledProcessError, Popen

def check_output(*args, **kwargs):
    process = Popen(stdout=PIPE, *args, **kwargs)
    out, err = process.communicate()
    ret = process.poll()
    if ret:
        cmd = kwargs.get("args")
        if cmd is None:
            cmd = args[0]
        error = CalledProcessError(ret, cmd)
        error.out = out
        error.message = err
        raise error
    return out

try:
    out = check_output(["ls", "/home"], stderr=PIPE)
    df = Popen(["ls", "/home/non"], stdout=PIPE)
    output, err = df.communicate()
except CalledProcessError as e:
    print(e.message)
else:
    print(out)

型

根据subprocess文档，现在首选run命令。
范例：

import logging
import subprocess

logger = logging.getLogger(__name__)

try:
    subprocess.run(["ls", "-l"], shell=True, check=True, capture_output=True)
except subprocess.CalledProcessError as err:
    logger.error(f"{err} {err.stderr.decode('utf8')}")

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正如其他人所提到的，如果你想保存到一个文件，你可以使用stdout参数到run;但是，你也可以使用use logging to do that，然后在你的方法中记录错误。