Quickie script to parallelize_jobs across cores on one processor using python's multiprocessing module. Essentially it's a poor man's version of GNU parallel.

parallelize_jobs.py

import os
import sys
import shlex
import argparse
import multiprocessing
from subprocess import Popen, PIPE

def get_args():
    """Processes arguements"""
    parser = argparse.ArgumentParser()
    
    parser.add_argument('-i','--infile', 
                        nargs='?', 
                        type=argparse.FileType('r'),
                        default=sys.stdin, 
                        help='File containing commands; one per line. \
                        Alternately accepts lines redirected from STDIN.\
                        (e.g. "python parallelize_jobs.py -n 2 < cmds.txt")')
    
    parser.add_argument('-n','--cores', 
                        type=int,
                        default=multiprocessing.cpu_count(),
                        help='Number of cores to use. Defaults to \
                        the number of available cores.')

    parser.add_argument('-q','--quiet', 
                        action='store_true', 
                        help="Setting this flag turns off output printing.")
    
    return parser.parse_args()

def job_runner(line):
    """Runs each job. Line needs to be properly parsable by shlex split."""
    cli_parts = shlex.split(line)
    ft = Popen(cli_parts, stdin=PIPE, stderr=PIPE, stdout=PIPE).communicate()
    return ft

def main():
    args = get_args()
    pool = multiprocessing.Pool(args.cores)

    # Clean lines, but don't read them into memory.
    # Skip lines that are comments and/or start with #.
    ilines = (line.strip() for line in args.infile \
              if line.startswith('#') is not True)

    # Do not print output if -q/--quiet flag is set
    if args.quiet is False:
        for result in pool.map(job_runner, ilines):
            for line in result:
                sys.stdout.write(line) 

if __name__ == "__main__":
    main()

Any reason why not to use GNU Parallel instead? Both require installing a single script. wget http://git.savannah.gnu.org/cgit/parallel.git/plain/src/parallel; chmod 755 parallel