Execute command using a subprocess and write streaming output to the screen

exec_cmd.py

def execute_command(cmd, shell_flag=False):
    """
    Execute command using a subprocess, and write streaming output to the screen with 0.5 sec delay.

    :param cmd: Command-line statement
    :param shell_flag: Flag to run subprocess in a shell (default: False)
    """
    with io.open("tmp_output.log", 'wb') as writer, io.open("tmp_output.log", 'rb', 1) as reader:
        p = subprocess.Popen(cmd, stdout=writer, shell=shell_flag)
        while p.poll() is None:
            sys.stdout.write(reader.read().decode('utf-8'))
            time.sleep(0.5)
        sys.stdout.write(reader.read().decode('utf-8'))