Python display subprocess stdout in real time

subprocess_stdout_instantly.py

# Redirect stderr and stdout of a subprocess to the python ones

def exec_cmd_with_output(cmd):
    stdoutlines = []
    a_process = subprocess.Popen(shlex.split(cmd), stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
    while a_process.poll() is None:
        line = a_process.stdout.readline()
        stdoutlines.append(line)
        sys.stdout.write(line.decode(sys.stdout.encoding))
    return a_process.returncode, stdoutlines


def exec_cmd_with_output_with_verbosity(cmd, verbos = 0):
    #log_debug("Launching command: '%s'" % cmd)
    if verbos < 0:
        fd_devnull = open(os.devnull, 'w')
        a_process = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, shell=True)
        a_process.wait()
        stdoutlines = None
        fd_devnull.close()
    else:
        stdoutlines = []
        a_process = subprocess.Popen(shlex.split(cmd), stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
        while a_process.poll() is None:
            line = a_process.stdout.readline()
            stdoutlines.append(line)
            sys.stdout.write(line.decode(sys.stdout.encoding))
    return a_process.returncode, stdoutlines