python - 使用带有 traceroute 的子进程时没有错误输出

Question

我正在尝试获取 traceroute 失败时返回的错误消息。例如:

from subprocess import CalledProcessError, check_output

try: 
    output = check_output(["traceroute", "error"])
except CalledProcessError as error:
    output = error.output

print "error: {}".format(output)

输出:

error:

我试过使用 output = str(error.output) 但输出保持为空。执行上述代码时会在终端打印错误信息，所以应该可以将其赋值给一个变量吧？

Answer 1

如中所述:https://docs.python.org/2/library/subprocess.html#subprocess.check_output

To also capture standard error in the result, use stderr=subprocess.STDOUT

尝试:

import subprocess
from subprocess import CalledProcessError, check_output

try: 
    output = check_output(["traceroute", "error"], stderr=subprocess.STDOUT)
except CalledProcessError as error:
    output = error

print "error: {}".format(output.output)

输出:

error: traceroute: unknown host error