[Tutor] nested os.popen()

Danny Yoo dyoo at hkn.eecs.berkeley.edu
Tue May 3 23:50:29 CEST 2005



On Tue, 3 May 2005, Jules Bravo wrote:

> I'm trying to create a program that can recreate the unix pipe. So
> basically I need to be able to take something like "ls *.py | du | wc"
> and be able to run it just like unix would, doing a wordcount of the du
> of all files that end with .py. My question is how would I do this
> without being able to create pipes that have both read and write
> capabilities.


Hi Jules,

You may want to look at the 'subprocess' module:

    http://www.python.org/doc/lib/module-subprocess.html


The documentation in:

    http://www.python.org/doc/lib/node237.html

shows how to implement pipelines.  The example is slightly cut down, since
you'll probably need to add something like:

######
from subprocess import Popen, PIPE
######

to make it work.  But, otherwise, it should be self-contained.


If you have more questions, please feel free to ask.  Good luck!



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