Question

我的pd如下：

df=
              CreationDate
0  2008-11-04 13:21:39
1  2008-11-24 23:50:29
2  2009-05-18 07:46:48
3  2009-09-22 06:03:34
4  2009-11-07 07:28:21
5  2009-12-08 14:29:56
6  2010-01-12 06:42:00
7  2010-05-20 17:56:01
8  2010-06-05 19:27:02
9  2010-07-16 19:52:22
10 2010-07-25 16:27:13
11 2010-07-25 21:59:56
CreationDate    datetime64[ns]
dtype: object

现在我需要在特定时间内选择和计数项目，例如，我需要这些项目并计算它们的形式＆＃39; 2008-11＆＃39;至2009-12＆＃39;。如何选择和统计？感谢。

Answer 1

您需要先将CreationDate设为索引，然后使用切片'2008-11':'2009-12'进行选择。

print(df)

          CreationDate       A
0  2008-11-04 13:21:39  1.7641
1  2008-11-24 23:50:29  0.4002
2  2009-05-18 07:46:48  0.9787
3  2009-09-22 06:03:34  2.2409
4  2009-11-07 07:28:21  1.8676
5  2009-12-08 14:29:56 -0.9773
6  2010-01-12 06:42:00  0.9501
7  2010-05-20 17:56:01 -0.1514
8  2010-06-05 19:27:02 -0.1032
9  2010-07-16 19:52:22  0.4106
10 2010-07-25 16:27:13  0.1440
11 2010-07-25 21:59:56  1.4543

# processing
# ==========================
df.set_index('CreationDate')['2008-11':'2009-12']

                          A
CreationDate               
2008-11-04 13:21:39  1.7641
2008-11-24 23:50:29  0.4002
2009-05-18 07:46:48  0.9787
2009-09-22 06:03:34  2.2409
2009-11-07 07:28:21  1.8676
2009-12-08 14:29:56 -0.9773

在Pandas中选择和计数项目datetime64 [ns]

1 个答案: