hive中如何调用python函数

ADD FILE /home/taobao/dw_hive/hivelets/smoking/ext/tsa/hivesql/bjx_topic_t1/splitsysin.py.bak;
create table if not exists splittest_t1
(
topic_id string,
topic_title string,
topic_desc string,
biz_date string,
gmt_create string
) PARTITIONED BY(pt string)
row format delimited fields terminated by '\001'
lines terminated by '\n'
STORED AS textfile;

select TRANSFORM(topic_id,topic_title,topic_desc,biz_date,gmt_create)
USING 'splitsysin.py'
as topic_id,topic_title,topic_desc,biz_date,gmt_create
from r_bjx_dim_topic_t1;