[Tutor] Correct way to call an outside program?

[Kent Johnson]

Allen Fowler wrote:
> Hello,
> 
> I need to call an external command line .exe utility from my Python script.
> 
> What is the best way to capture the output (if any) and (optionally) direct it to my normal standard output?

subprocess.Popen().communicate() will do it:

In [1]: import subprocess
In [7]: x=subprocess.Popen('ls', stdout=subprocess.PIPE, 
stderr=subprocess.PIPE).communicate()
In [10]: print x[0]
...

If you just want stdout and stderr of the subprocess to go to stdout and 
stderr of the calling process you can omit those arguments to Popen().

Kent