Subprocess.Popen('python -v',stdout=PIPE,stderr=PIPE,Shell=True)

Prduces output in stderr instead of stdout.

For others: pip --version or git --version output is in stdout and is expected.

-v writes to stderr, so this is the expected behavior. Although maybe this could be better documented.

See issue 18338, where this was briefly discussed and a change was rejected.

Maybe you're looking for -V (uppercase) or --version, which do write to stdout, at least in 3.x. I'm not sure where they write in 2.7, but it's much too late to change 2.7's behavior.

I'm going to close this. If you find some of our documentation that says -v writes to stdout, then we can reopen this.

This is not a Windows specific error, so I'm modifying the nosy list.

Hello,

-V and --version both write to stderr not stdout.

On Thu, 3 Jan 2019, 1:29 pm Eric V. Smith <report@bugs.python.org wrote:

>
> Eric V. Smith <eric@trueblade.com> added the comment:
>
> -v writes to stderr, so this is the expected behavior. Although maybe this
> could be better documented.
>
> See issue 18338, where this was briefly discussed and a change was
> rejected.
>
> Maybe you're looking for -V (uppercase) or --version, which do write to
> stdout, at least in 3.x. I'm not sure where they write in 2.7, but it's
> much too late to change 2.7's behavior.
>
> I'm going to close this. If you find some of our documentation that says
> -v writes to stdout, then we can reopen this.
>
> This is not a Windows specific error, so I'm modifying the nosy list.
>
> ----------
> components: +Interpreter Core -Windows, ctypes
> nosy: +eric.smith -paul.moore, steve.dower, tim.golden, zach.ware
> resolution:  -> not a bug
> stage:  -> resolved
> status: open -> closed
> title: Subprocess.Popen('python -v',stdout=PIPE,stderr=PIPE,Shell=True)
> gives output in stderr -> python -v writes to stderr
>
> _______________________________________
> Python tracker <report@bugs.python.org>
> <https://bugs.python.org/issue35646>
> _______________________________________
>

That's just the way it is with 2.7.

Thank you for the reply Eric.
Thought the behaviour is pretty wierd and opened the issue.

On Thu, 3 Jan 2019, 2:28 pm Eric V. Smith <report@bugs.python.org wrote:

>
> Eric V. Smith <eric@trueblade.com> added the comment:
>
> That's just the way it is with 2.7.
>
> ----------
>
> _______________________________________
> Python tracker <report@bugs.python.org>
> <https://bugs.python.org/issue35646>
> _______________________________________
>