'Get the latest data with a shell command.'

def update(self):

    _LOGGER.info('Running    command:    %s', self.command)
    try:
        return_value = subprocess.check_output(self.command, shell=True, timeout=15)
        self.value = return_value.strip().decode('utf-8')
    except subprocess.CalledProcessError:
        _LOGGER.error('Command    failed:    %s', self.command)
    except subprocess.TimeoutExpired:
        _LOGGER.error('Timeout    for    command:    %s', self.command)
