def start_test_suite(test_suite, config):
    """
    test_suite is the path to the binary test suite
    config is the path to the configuration file
    """
    args = ['ttcn3_start', test_suite, config]
    child = subprocess.Popen(args, stdout=subprocess.PIPE)
    return child

child_process = start_test_suite(test_suite, config)
line = 'initialize line'
while line != '':
    line = child_process.stdout.readline().decode("utf-8")
    if 'finished. Verdict:' in line:
        # here you should have lines like: "MTC@lx: Test case [TC] finished. Verdict: pass reason: [your reason]
        # grab the verdict with regex: the verdict result is between the keyword 'Verdict:' and 'reason:'
        # e.g. something like matches = re.finditer(r'Verdict:\s(.*)reason:') 

child_process.terminate()