如何从python中的timedelta64 [ns]对象中提取整数天数

Question

我有一个pandas数据框，其列如：

In [96]: data['difference']
Out[96]: 
0                 NaT
1     1 days 21:34:30
2     0 days 16:57:36
3     0 days 00:16:51
4     0 days 15:52:38
5     0 days 14:19:34
6     0 days 02:54:46
7     1 days 04:21:28
8     0 days 01:58:55
9     0 days 10:30:35
10    0 days 07:53:04
....
Name: difference, dtype: timedelta64[ns]

我想在它旁边创建一个整数列，该列对应于此列中的日期值。

Answer 1

这会将您的timedelta64[ns]类型转换为代表日期的float64：

data['difference'].astype('timedelta64[D]')

Answer 2

您可以使用dt.days从系列中提取几天，

df.difference
Out[117]: 
0   -1 days +00:00:05
1                 NaT
2   -1 days +00:00:05
3     1 days 00:00:00
dtype: timedelta64[ns]

df.difference.dt.days
Out[118]: 
0    -1
1   NaN
2    -1
3     1
dtype: float64

所有其他组件提取，

dr
Out[93]: 
0   -1 days +00:00:05
1                 NaT
2     1 days 02:04:05
3     1 days 00:00:00
dtype: timedelta64[ns]

dr.dt.components
Out[95]: 
   days  hours  minutes  seconds  milliseconds  microseconds  nanoseconds
0    -1      0        0        5             0             0            0
1   NaN    NaN      NaN      NaN           NaN           NaN          NaN
2     1      2        4        5             0             0            0
3     1      0        0        0             0             0            0

Answer 3

如果您可以将输出作为字符串输出，那么python应该会有所帮助。

''.join(item[0]+',' for item in re.findall('[0-9]+ days', output))[:-1]