我正在使用以下DataFrame，并且只想访问DateTimeIndex的时间（不是日期）：
idle wheel Induce wheel axial radial
tiempo
5/30/2016 19:37:46 -1,099.12 -1,048.78 -477.13
5/30/2016 19:37:47 -1,099.12 -1,048.78 -476.98
5/30/2016 19:37:48 -1,099.12 -1,048.78 -477.21
5/30/2016 19:37:49 -1,099.12 -1,048.78 -477.13
5/30/2016 19:37:50 -1,099.12 -1,048.78 -477.21
5/30/2016 19:37:51 -1,099.12 -1,048.78 -477.35
5/30/2016 19:37:52 -1,099.12 -1,048.78 -477.13
5/30/2016 19:37:53 -1,099.12 -1,048.78 -476.98
5/30/2016 19:37:54 -1,099.12 -1,048.78 -476.98
5/30/2016 19:37:55 -1,099.12 -1,048.78 -476.98
5/30/2016 19:37:56 -1,099.12 -1,048.78 -476.98
5/30/2016 19:37:57 -1,099.12 -1,048.78 -476.98
我想只保留19:..:..，而不是日期部分。
我一直在寻找，但无法找到任何解决方案。
答案 0 :(得分：2)
在.time index上使用'tiempo'：
df['time'] = df.index.time
或，如果'tiempo'是column使用
df['time'] = df.tiempo.dt.time
得到：
tiempo idle wheel Induce wheel axial radial time
0 2016-05-30 19:37:46 -1099.12 -1048.78 -477.13 19:37:46
1 2016-05-30 19:37:47 -1099.12 -1048.78 -476.98 19:37:47
2 2016-05-30 19:37:48 -1099.12 -1048.78 -477.21 19:37:48
3 2016-05-30 19:37:49 -1099.12 -1048.78 -477.13 19:37:49
4 2016-05-30 19:37:50 -1099.12 -1048.78 -477.21 19:37:50
5 2016-05-30 19:37:51 -1099.12 -1048.78 -477.35 19:37:51
6 2016-05-30 19:37:52 -1099.12 -1048.78 -477.13 19:37:52
7 2016-05-30 19:37:53 -1099.12 -1048.78 -476.98 19:37:53
8 2016-05-30 19:37:54 -1099.12 -1048.78 -476.98 19:37:54
9 2016-05-30 19:37:55 -1099.12 -1048.78 -476.98 19:37:55
10 2016-05-30 19:37:56 -1099.12 -1048.78 -476.98 19:37:56
11 2016-05-30 19:37:57 -1099.12 -1048.78 -476.98 19:37:57