pandas groupby with datetimeindex

Question

grouped = data.groupby('LA_DECH')
start = date(2016, 1, 1)
end = date(2016, 12, 31)
rng = pd.date_range(start, end, freq='BM')

有没有一种简单的方法来通过这种比较来提取数据(df列表)：rng中每个周期的'2016/1/1' < grouped['LA_DECH] < '2016/2/29'和this

Answer 1

至少对我来说，你没有很好地说明你的问题和你想要得到的东西。你是说这个吗？

import pandas as pd
import numpy as np
from datetime import datetime

start = datetime(2016,1,1)
end = datetime(2016,12,31)
idx = pd.date_range('2015-01-01','2017-09-01')
df = pd.DataFrame(np.random.randint(10,size= (len(idx),2)), index= idx, columns=['VALUE',"LA_DECH"])

rng = pd.date_range(start, end, freq='BM')
# filted by start and end date
df = df[(df.index>start)&(df.index <end)] # this line is not necessary needed
print(df.groupby([pd.cut(df.index,rng), 'LA_DECH'])['LA_DECH'].count())

                                LA_DECH
(2016-01-29, 2016-02-29]  0          2
                          2          1
                          3          5
                          4          2
                          5          3
                          6          4
                          7          4
                          8          5
                          9          5
(2016-02-29, 2016-03-31]  0          4
                          2          1
                          3          4
                          4          5
                          5          2
                          6          3
                          7          3
                          8          6
                          9          3

                                ..
(2016-08-31, 2016-09-30]  8          2
                          9          1
(2016-11-30, 2016-12-30]  0          2
                          1          1
                          2          1
                          3          1
                          4          1
                          5          5
                          6          3
                          7          5
                          8          5
                          9          6
Name: LA_DECH, Length: 104, dtype: int64