passing command line arguments to executable

Patrick Maupin pmaupin at
Sat Apr 3 19:29:49 CEST 2010

On Apr 3, 12:20 pm, mcanjo <mca... at> wrote:
> On Apr 3, 11:15 am, Patrick Maupin <pmau... at> wrote:
> > On Apr 3, 11:09 am, mcanjo <mca... at> wrote:
> > > I have an executable (I don't have access to the source code) that
> > > processes some data. I double click on the icon and a Command prompt
> > > window pops up. The program asks me for the input file, I hit enter,
> > > and then it asks me for and output filename, I hit enter a second time
> > > and it goes off and does its thing and when it is finished running the
> > > Command Prompt goes away and I have my new output file in the same
> > > directory as my executable and input file. I would like to be able to
> > > batch process a group of files. I thought about using "os.spawnv()" in
> > > a loop and at each iteration of the loop passing in the file in and
> > > out names but that didn't work. Does anyone have any ideas?
> > You need to look at the subprocess module, and use pipes.
> > Regards,
> > Pat
> I tried doing the following code:
> from subprocess import Popen
> from subprocess import PIPE, STDOUT
> exefile = Popen('pmm.exe', stdout = PIPE, stdin = PIPE, stderr =
> exefile.communicate('MarchScreen.pmm\nMarchScreen.out')[0]
> and the Command Prompt opened and closed, no exceptions were generated
> but the program didn't run. Am I doing something wrong?

I don't use communicate because I've never gotten it to do what I
want.  I also don't use Windows.  I have a linux solution that allows
me to feed stuf into a pipe, but I don't think it will work under
Windows because it uses os functions to block on empty pipes that
Windows doesn't support.

You might read PEP 3145 -- it addresses some of the issues, and there
is some code to help, I think:


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