Running a subprocess in a venv

[Larry Martell]

On Sat, Oct 21, 2023 at 12:10 PM Johannes Findeisen <mailman at hanez.org> wrote:
>
> On Sat, 21 Oct 2023 11:32:03 -0400
> Larry Martell <larry.martell at gmail.com> wrote:
>
> > On Sat, Oct 21, 2023 at 9:49 AM Johannes Findeisen
> > <mailman at hanez.org> wrote:
> > >
> > > On Sat, 21 Oct 2023 09:01:18 -0400
> > > Larry Martell via Python-list <python-list at python.org> wrote:
> > >
> > > > I have a python script, and from that I want to run another
> > > > script in a subprocess in a venv. What is the best way to do
> > > > that? I could write a file that activates the venv then runs the
> > > > script, then run that file, but that seems messy. Is there a
> > > > better way?
> > >
> > > How do you do that?
> >
> > How? Open a file and write the commands I need then invoke that.
> >
> > > It sounds messy but not wrong...
> > >
> > > I would activate the venv and then run my Python script. In the
> > > Python script you can call another python script in a subprocess
> > > like this:
> > >
> > > import sys
> > > import subprocess
> > >
> > > #
> > > https://docs.python.org/3/library/subprocess.html#popen-constructor
> > > proc = subprocess.Popen([sys.executable,
> > > "/path/to/an/otherscript.py"])
> > >
> > > # https://docs.python.org/3/library/subprocess.html#popen-objects
> > > # Do your process communication/handling... proc.communicate(),
> > > # proc.wait(), proc.terminate(), proc.kill() etc.
> > >
> > > Is this the answer you are looking for?
> > >
> > > Detailed docs: https://docs.python.org/3/library/subprocess.html
> >
> > I know how to use Popen. What I was missing was running the script
> > using sys.executable. Thanks.
>
> sys.executable is the path to the actual Python binary, e.g.
> "/usr/bin/python". You could add "/usr/bin/python" there manually but
> this is not portable to Windows for example.
>
> When you add a shebang line to your other script and the file is
> executable, you may not need to add sys.executable as first argument to
> Popen but using sys.executable is the most reliable way to do this... ;)

I need the path to whichever venv is being used so sys.executable works for me.