CODEWITHSUNDEEP
pythonlinuxsubprocess
ashleh
ashleh

Reputation: 225

How to use the indexes in a list within the subprocess module?

not used python much so still learning. Basically, I have a list of IDs which relate to a specific job. At the moment I just want to be able to pass the first ID in the list (using the a[0]) and print the output of the request to hello.txt. So the entire command itself is going to look like bjobs -l 000001 > hello.txt. Once I've got this done, I can loop through the entire file of IDs to create a separate file for each command output.

#! /usr/bin/python

import subprocess

a = [ln.rstrip() for ln in open('file1')]

subprocess.call(["bjobs -l ", a[0], "> hello.txt"], shell=True)

Any help would be appreciated! If I haven't made myself clear on something then please ask and I'll try and explain.

Upvotes: 3

Views: 128

Answers (2)

Rik Poggi
Rik Poggi

Reputation: 29302

If you want just the first id, do:

with open('file1') as f:
    first_id = next(f).strip()

The with statement will open the file and make sure to close it.

Then you could get the bjobs output with something like:

output = subprocess.check_output(["bjobs", "-l", first_id], shell=True)

And write:

with open('hello.txt', 'wb') as f:
    f.write(output)

I'm suggesting to separate the fetching and writing of the bjobs output beacuse you might want to do something on it or maybe you'll write the bjobs in Python so... Well this will keep things separated.

If you want to loop on all the ids, you can do it:

with open('file1') as f:
    for line in f:
        line = line.strip()
        # ...

Or with enumerate if you need the line number:

with open('file1') as f:
    for i, line in enumerate(f):
        line = line.strip()
        # ...

I know that I went a little ahead of what you asked, but it seems like you're starting to build something, so I thought it might be useful.

Upvotes: 3

Alfe
Alfe

Reputation: 59426

How about this file, named spam.py:

with open('file1') as f:
  for line in f:
    subprocess.call([ 'bjobs', '-l', line.rstrip() ])

Then call it using python spam.py > hello.txt.

Upvotes: 1

Related Questions