map: cfmr_itembased_step1_normalization_m.py
# coding=utf-8
'''
step1:将每个item的基于所有的uid给出的score归一处理
cat testdata/ratings_small.csv | python cfmr_itembased_step1_normalization_m.py |sort -k 1 |python cfmr_itembased_step1_normalization_r.py
将rating数据转换为 iid,uid,score形式
'''
import sys
for line in sys.stdin:
u, i, s, t = line.strip().split(',')
if u.isdigit():
print( "%s\t%s\t%s" % (i, u, s))