goodDiskName2016

from  datetime import datetime
from time import time

直接方括號定位相等的列

start = time()
for disk in goodDiskName2016[:100]:
                　____ST4000DM000_2016_good_feature27[ST4000DM000_2016_good_feature27.serial_number==disk][features27[0]]
time()-start

消耗時間

82.93997383117676

直接loc定位相等的

start = time()
for disk in goodDiskName2016[:100
 
]:                                                 ____ST4000DM000_2016_good_feature27.loc[ST4000DM000_2016_good_feature27.serial_number==disk][features27[0]]
time()-start

消耗時間：

82.4887466430664

先將這一列設定為index，然後通過loc查詢

b = ST4000DM000_2016_good_feature27.set_index('serial_number')

start = time()
for disk in goodDiskName2016[:100
 
]:
    b.loc[disk][features27[0]]
time()-start

消耗時間：

   25.706212759017944

設定為index後用at定位

start = time()
for disk in goodDiskName2016[:100]:
    b.at[disk,features27[0]]
time()-start

消耗時間：

25.67607021331787