Windows Async process tracking

from time import sleep, time
import asyncio.subprocess
import sys
t0 = time()

@asyncio.coroutine
def start_process():
    script = """
from time import sleep

print('Lets count to 5')
for i in range(1, 6):
    sleep(1)
    print(i)

print('Good bye!')
    """

    # Create the subprocess, redirect the standard output into a pipe
    create = asyncio.create_subprocess_exec(sys.executable, '-c', script,
                                            stdout=asyncio.subprocess.PIPE,
                                            bufsize=0)
    proc = yield from create
    return proc

@asyncio.coroutine
def readline(proc):

    # Read one line of output
    data = yield from proc.stdout.readline()
    line = data.decode('ascii').rstrip()

    return line

@asyncio.coroutine
def follow_process():
    print('Starting Process')
    proc = yield from start_process()
    print('Following Process...')
    while proc.returncode is None:
        line = yield from readline(proc)
        sleep(0.01)
        if line:
            print(line)
        else:
            print('.', end='')

    print()
    print('Return Code', proc.returncode)


if sys.platform == "win32":
    loop = asyncio.ProactorEventLoop()
    asyncio.set_event_loop(loop)
else:
    loop = asyncio.get_event_loop()

loop.run_until_complete(follow_process())
print('done')
loop.close()