Parse a shell command with pipe characters, into a subprocess chain

pipes_to_subprocess.py

import subprocess as sub 

def create_pipes(cmd):
    procs = {}
    parts = cmd.split('|')
    for i, part in enumerate(parts):
        cmdparts = part.strip().split(' ')

        if i == 0:
            procs[i] = sub.Popen(cmdparts, stdout=sub.PIPE)
        else:
            procs[i] = sub.Popen(cmdparts, stdin=procs[i-1].stdout, stdout=sub.PIPE)

    print procs[len(procs)-1].communicate()[0]
    for proc in procs.values():
        proc.stdout.close()

if __name__ == '__main__':
    create_pipes("echo hej | tr 'e' 'a' | tee out.log")