new to Python - modules to leverage Perl scripts?

[Peter Otten]

Rogelio wrote:

> I've got quite a few Perl scripts that I would like to leverage, and
> I'd like to make some Python wrapper scripts for them.
> 
> The Perl scripts shell into various network appliances, run certain
> commands, and then output those commands into a file.
> 
> I recently found out about the subprocess modules (including "call")
> and am wondering what other Python libraries and modules I should
> check out.  Specifically, I need functions that will do the
> following...
> 
> 1) Take a big IP file and break it up into smaller chunks (e.g. 20 IP
> addresses per file)

itertools.islice()

> 2) Run the Perl script on those smaller IP files

subprocess. If the script can read from stdin you may not need the 
intermediate file; use 

subprocess.Popen(..., stdin=PIPE).communicate(inputdata_as_a_string)

instead.

> 3) Run the Perl commands in parallel (to take less time)

multiprocessing? Though your problem may be I/O-bound.

> 4) Take the little logs and concatenate the files

itertools.chain.from_iterable()

> 5) Look for existence of certain strings in the logs

with open(logfile) as f:
    for line in f:
        if some_string in line:
            # whatever

If you know Perl you will not be completely puzzled when you have to switch 
to a regex. You'll rather make that switch to early ;)
 
> I'm still playing with the subprocess.call command to make sure that
> it calls everything okay.  But I'm hoping someone can point me where
> to look for functions that will make this an effective wrapper script.

You sound like you are not completely satisfied with subprocess. What are 
you missing?