Python OS system call with subprocess

sync.py

import sys
import os
import subprocess

# Set sync source & destination
source_path = "temp/a"
dest_path = "temp/b"

# Sync: source_path -> mountpoint
if sys.platform.startswith('win'):
    # Windows: Robocopy.exe
    cmd = [
        'Robocopy.exe',
        os.path.abspath(source_path),
        os.path.abspath(dest_path),
        '/MIR', '/Z', '/W:5',
    ]

else:
    # Linux: rsync
    cmd = [
        'rsync',
        '-aIvzh', '--delete',
        "{}/".format(os.path.abspath(source_path)),
        "{}/".format(os.path.abspath(dest_path)),
    ]

# Create & Run process
process = subprocess.Popen(
    cmd, shell=True,
    stdout=subprocess.PIPE,
    stderr=subprocess.PIPE,
)
for line in process.stdout:
    process.poll()
    print(line.decode().rstrip('\n'))
process.wait()
print("Process finished with return code: {}".format(process.returncode))