如何以分钟（浮动）为单位转换（可能为负）Pandas TimeDelta？

Question

我有一个这样的数据框

df[['timestamp_utc','minute_ts','delta']].head()
Out[47]: 
            timestamp_utc           minute_ts                    delta
0 2015-05-21 14:06:33.414 2015-05-21 12:06:00 -1 days +21:59:26.586000
1 2015-05-21 14:06:33.414 2015-05-21 12:07:00 -1 days +22:00:26.586000
2 2015-05-21 14:06:33.414 2015-05-21 12:08:00 -1 days +22:01:26.586000
3 2015-05-21 14:06:33.414 2015-05-21 12:09:00 -1 days +22:02:26.586000
4 2015-05-21 14:06:33.414 2015-05-21 12:10:00 -1 days +22:03:26.586000

在哪里 df['delta']=df.minute_ts-df.timestamp_utc

timestamp_utc     datetime64[ns]
minute_ts         datetime64[ns]
delta            timedelta64[ns]

问题是，我想获得和之间的（可能是负数）分钟数，timestamp_utc而minutes_ts忽略秒部分。

所以对于第一行，我想得到-120. 确实，2015-05-21 12:06:00是120分钟前2015-05-21 14:06:33.414。

最熊猫式的方法是什么？

非常感谢！

Answer 1

您可以使用：

df['a'] = df['delta'] / np.timedelta64(1, 'm')
print (df)
            timestamp_utc           minute_ts                    delta  \
0 2015-05-21 14:06:33.414 2015-05-21 12:06:00 -1 days +21:59:26.586000   
1 2015-05-21 14:06:33.414 2015-05-21 12:07:00 -1 days +22:00:26.586000   
2 2015-05-21 14:06:33.414 2015-05-21 12:08:00 -1 days +22:01:26.586000   
3 2015-05-21 14:06:33.414 2015-05-21 12:09:00 -1 days +22:02:26.586000   
4 2015-05-21 14:06:33.414 2015-05-21 12:10:00 -1 days +22:03:26.586000   

          a  
0 -120.5569  
1 -119.5569  
2 -118.5569  
3 -117.5569  
4 -116.5569  

然后转换float为int：

df['a'] = (df['delta'] / np.timedelta64(1, 'm')).astype(int)
print (df)
            timestamp_utc           minute_ts                    delta    a
0 2015-05-21 14:06:33.414 2015-05-21 12:06:00 -1 days +21:59:26.586000 -120
1 2015-05-21 14:06:33.414 2015-05-21 12:07:00 -1 days +22:00:26.586000 -119
2 2015-05-21 14:06:33.414 2015-05-21 12:08:00 -1 days +22:01:26.586000 -118
3 2015-05-21 14:06:33.414 2015-05-21 12:09:00 -1 days +22:02:26.586000 -117
4 2015-05-21 14:06:33.414 2015-05-21 12:10:00 -1 days +22:03:26.586000 -116