def time_now_with_foramt(format='%Y-%m-%d %H:%M:%S'):
    """
    Returning a formatted string of time

    @Args:
    * [format] str, something like %Y-%m-%d %H:%M:%S.%f

    @Returns:
    * [str] the formatted string of time
    """
    import datetime
    return datetime.datetime.now().strftime(format)
