python pandas中两个datetime.time列之间的微秒差异？

Question

我有一个python pandas数据框,其中包含2列:time1和time2:

     time1             time2
13:00:07.294234    13:00:07.294234 
14:00:07.294234    14:00:07.394234 
15:00:07.294234    15:00:07.494234 
16:00:07.294234    16:00:07.694234 

如何生成第三列,其中包含time1和之间的微秒差异time2,如果可能的话,是整数？

Answer 1

如果在 hese 前面加上实际日期，则可以将它们转换为 datetime64 列：

In [11]: '2014-03-19 ' + df
Out[11]: 
                        time1                       time2
0  2014-03-19 13:00:07.294234  2014-03-19 13:00:07.294234
1  2014-03-19 14:00:07.294234  2014-03-19 14:00:07.394234
2  2014-03-19 15:00:07.294234  2014-03-19 15:00:07.494234
3  2014-03-19 16:00:07.294234  2014-03-19 16:00:07.694234

[4 rows x 2 columns]

In [12]: df = ('2014-03-19 ' + df).astype('datetime64[ns]')
Out[12]: 
                       time1                      time2
0 2014-03-19 20:00:07.294234 2014-03-19 20:00:07.294234
1 2014-03-19 21:00:07.294234 2014-03-19 21:00:07.394234
2 2014-03-19 22:00:07.294234 2014-03-19 22:00:07.494234
3 2014-03-19 23:00:07.294234 2014-03-19 23:00:07.694234

现在您可以减去这些列：

In [13]: delta = df['time2'] - df['time1']

In [14]: delta
Out[14]: 
0          00:00:00
1   00:00:00.100000
2   00:00:00.200000
3   00:00:00.400000
dtype: timedelta64[ns]

要获得微秒数，只需将底层纳秒除以 1000：

In [15]: t.astype(np.int64) / 10**3
Out[15]: 
0         0
1    100000
2    200000
3    400000
dtype: int64

正如杰夫指出的那样，在最近版本的 numpy 上，您可以除以 1 微秒：

In [16]: t / np.timedelta64(1,'us')
Out[16]: 
0         0
1    100000
2    200000
3    400000
dtype: float64