@classmethod
def select_one(cls, **kwargs):
    key = list(kwargs.keys())[0]
    value = kwargs[key]
    sql = ('select * from %s where %s=?' % (cls.table_name, key))
    sql = sql.replace('?', '%s')
    ms = mysql_conn.Mysql()
    re = ms.select(sql, value)
    if re:
        return cls(**re[0])
    else:
        return
@classmethod
def select_one(cls, **kwargs):
    key = list(kwargs.keys())[0]
    value = kwargs[key]
    sql = ('select * from %s where %s=?' % (cls.table_name, key))
    sql = sql.replace('?', '%s')
    ms = mysql_conn.Mysql()
    re = ms.select(sql, value)
    if re:
        return cls(**re[0])
    else:
        return