subprocess.popen question

[Eric_Dexter at msn.com]

On Jun 20, 1:46 pm, "Gabriel Genellina" <gagsl-... at yahoo.com.ar>
wrote:
> En Wed, 20 Jun 2007 12:27:47 -0300, Eric_Dex... at msn.com  
> <Eric_Dex... at msn.com> escribió:
>
> > I am trying to modify a programming example and I am coming up with
> > two problems...  first is that I can't seem to pass along the
> > arguments to the external command (I have been able to do that with
> > the old module and cmd is the command I wish to try) all the output
> > seems to be returned as one line (at least when I run the program in
> > spe).
>
> > import subprocess
> > from os import system
> > cmd = """gawk -f altertime.awk -v time_offset=4 -v
> > outfile="testdat.sco" "i1.sco" """
> > #subprocess.Popen.
> > last_line = subprocess.Popen(['gawk.exe'],
> > stdout=subprocess.PIPE).communicate()[0]
>
> You build what appears to be the desired command line, but execute  
> gawk.exe instead.
> Better split the arguments beforehand:
> cmd = ["gawk", "-f", "altertime.awk", "-v", "time_offset=4", "-v",  
> "outfile=testdat.sco", "i1.sco"]
> Now, what do you want to do with the output? Printing it line by line?
> output = subprocess.Popen(cmd, stdout=subprocess.PIPE).communicate()[0]
> lines = output.splitlines()
> for line in lines:
>    print line
>
> --
> Gabriel Genellina

 C:\dex_tracker\pipe1.py
Traceback (most recent call last):
 File "C:\dex_tracker\pipe1.py", line 14, in
last_line = subprocess.Popen([cmd],
stdout=subprocess.PIPE).communicate()[0]
 File "C:\Python25\lib\subprocess.py", line 593, in __init__
errread, errwrite)
 File "C:\Python25\lib\subprocess.py", line 793, in _execute_child
startupinfo)
WindowsError: [Error 2] The system cannot find the file specified
Script terminated.

I can write it out as a batch file and then run it but that is a messy
hack..