python 批量修改/替换数据

在进行数据操作时，经常会根据条件批量的修改数据，如以下数据，按照日期的条件，将部门日期下的promotion改为1

	tot_qty	price	date	price_delta1	price_delta2	price_delta3	promotion
created_date
20160419	1.0	5.410000	20160419	NaN	NaN	NaN	0
20161111	96.0	5.400000	20161111	-0.010000	NaN	NaN	1
20161123	1.0	7.500000	20161123	2.100000	2.090000	NaN	0
20161213	5.0	7.500000	20161213	0.000000	2.100000	2.090000	0
20161226	37.0	6.258571	20161226	-1.241429	-1.241429	0.858571	0

方法：遍历每一行，判断条件，执行修改

for i in range(len(data)):
    line=data.iloc[i,:]
    if line['date']in (20170416,20170417,20170418,20170616,20170617,20170618,20170816,20170817,20170818,20171109,20171110,20171111):
        data[i:i+1]['promotion']=1