Calling external program from within python

[Mike Driscoll]

On Jul 25, 9:28 am, "Diez B. Roggisch" <de... at nospam.web.de> wrote:
> Mike Driscoll schrieb:
>
> > On Jul 25, 7:56 am, Emmanouil Angelakis <angel... at mpifr-bonn.mpg.de>
> > wrote:
> >> Hi,
>
> >> I am tryiong to do something obviously trivial such as:
> >> I have a c program called "tsys2list" that when it is ran it asks the user to give the value of "tcal" which is a variable. I want to call the  "tsys2list" from within a pyrthon script lets call it "gamma.py" >>>but<<< I want to pass the value of "tcal" to th eprogram automatically and not by interacting with the keyboard.
>
> >> How do I do that?
>
> >> thanks i advance!
> >> manolis
>
> > There are probably many ways to do this. I would recommend checking
> > out the subprocess module and see if it does what you want.
>
> This will only work if the program can be fully controlled by
> commandline arguments. If interaction is required, the OP might consider
> using pexpect.
>
> > Or you
> > could learn a little Tkinter or wxPython and use that to get the
> > user's variable. Or you could even do it via the command line using
> > the "raw_input" command.
>
> I fail to see how *gathering* input (regardless of the method) solves
> the problem of *passing* input to a subprocess.
>
> Diez

My understanding of the OP's request was that "tsys2list" was a custom
script of some sort that gathered info from the user, so I wanted to
know why he didn't just skip calling it and write something in Tkinter
or wxPython or even via the CLI instead.

I'm probably just not understanding something.

Mike