def QA_util_random_with_topic(topic='Acc', lens=8):
    """
    生成account随机值

    Acc+4数字id+4位大小写随机

    """
    _list = [chr(i) for i in range(65,
                                   91)] + [chr(i) for i in range(97,
                                                                 123)
                                          ] + [str(i) for i in range(10)]

    num = random.sample(_list, lens)
    return '{}_{}'.format(topic, ''.join(num))