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:

我尝试使用output = str(error.output)但输出保持为空.执行上述代码时会向终端打印一条错误消息,因此应该可以将其分配给变量,对吧？

解决方法:

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

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