将 ``秒级别的时间戳`` 转换成字符串

    .. warning:
        时间戳是以 ``秒`` 为单位的

    :param timestamp: unix timestamp
    :type timestamp: int
    :param fmt: show format
    :type fmt: str
    :return:
    :rtype: str

def unixtime2str(timestamp, fmt='%Y-%m-%d %H:%M:%S'):
    """
    将 ``秒级别的时间戳`` 转换成字符串

    .. warning:
        时间戳是以 ``秒`` 为单位的

    :param timestamp: unix timestamp
    :type timestamp: int
    :param fmt: show format
    :type fmt: str
    :return:
    :rtype: str
    """
    dt = None
    try:
        timestamp = time.localtime(timestamp)
        dt = time.strftime(fmt, timestamp)
    except Exception as err:
        print(err)
    return dt