如何做一個滾動一週最新總和python的大熊貓

Question

假設我有以下代碼：

import pandas as pd 
frame = pd.DataFrame(
    { 
    "Date":["11/1/2017","11/2/2017","11/3/2017","11/4/2017", 
      "11/5/2017","11/6/2017","11/7/2017","11/8/2017","11/9/2017","11/10/2017","11/11/2017", 
      "11/12/2017"], 
    "Day":["Wed","Thr","Fri","Sat", 
      "Sun","Mon","Tue","Wed","Thr","Fri","Sat", 
      "Sun"], 
    "Sales":[5,5,10,5, 
       5,10,5,5,15,5,0, 
       5] 
    }) 
frame.reset_index() 
print(frame) 
print() 

frame['RollingSum']=frame["Sales"].rolling(window=7, min_periods = 1, win_type='boxcar').sum() 

print(frame) 

它打印輸出如下：

  Date Day Sales 
0 11/1/2017 Wed  5 
1 11/2/2017 Thr  5 
2 11/3/2017 Fri  10 
3 11/4/2017 Sat  5 
4 11/5/2017 Sun  5 
5 11/6/2017 Mon  10 
6 11/7/2017 Tue  5 
7 11/8/2017 Wed  5 
8 11/9/2017 Thr  15 
9 11/10/2017 Fri  5 
10 11/11/2017 Sat  0 
11 11/12/2017 Sun  5 

     Date Day Sales RollingSum 
0 11/1/2017 Wed  5   5.0 
1 11/2/2017 Thr  5  10.0 
2 11/3/2017 Fri  10  20.0 
3 11/4/2017 Sat  5  25.0 
4 11/5/2017 Sun  5  30.0 
5 11/6/2017 Mon  10  40.0 
6 11/7/2017 Tue  5  45.0 
7 11/8/2017 Wed  5  45.0 
8 11/9/2017 Thr  15  55.0 
9 11/10/2017 Fri  5  50.0 
10 11/11/2017 Sat  0  45.0 
11 11/12/2017 Sun  5  45.0 

現在假設，而不是平坦的7天窗口，我希望左端點是最近的星期日（或數據集中的第一天）......我怎麼能達到這個目標？所需的輸出：

  Date Day Sales  WTDSum 
0 11/1/2017 Wed  5   5.0 
1 11/2/2017 Thr  5  10.0 
2 11/3/2017 Fri  10  20.0 
3 11/4/2017 Sat  5  25.0 
4 11/5/2017 Sun  5   5.0 
5 11/6/2017 Mon  10  15.0 
6 11/7/2017 Tue  5  20.0 
7 11/8/2017 Wed  5  25.0 
8 11/9/2017 Thr  15  40.0 
9 11/10/2017 Fri  5  45.0 
10 11/11/2017 Sat  0  45.0 
11 11/12/2017 Sun  5   5.0 

Answer 1

我們組和組計算使用cumsum兩次

df['WTDSum']=df.groupby(df.Day.eq('Sun').cumsum()).Sales.cumsum() 
df 
Out[520]: 
      Date Day Sales WTDSum 
0 11/1/2017 Wed  5  5 
1 11/2/2017 Thr  5  10 
2 11/3/2017 Fri  10  20 
3 11/4/2017 Sat  5  25 
4 11/5/2017 Sun  5  5 
5 11/6/2017 Mon  10  15 
6 11/7/2017 Tue  5  20 
7 11/8/2017 Wed  5  25 
8 11/9/2017 Thr  15  40 
9 11/10/2017 Fri  5  45 
10 11/11/2017 Sat  0  45 
11 11/12/2017 Sun  5  5