I have a set of data [12, 13, 15, 16, 14, 11, 19, 24, 28, 25] and I want to sum every term/every fifth term. If less than three/five items are set as NaN, is there any way to quickly get the values of sum_3 and sum_5
num sum_3 sum_5
0 12 NaN NaN
1 13 NaN NaN
2 15 40 NaN
3 16 44 NaN
4 14 45 70
5 11 41 69
6 19 44 75
7 24 54 84
8 28 71 96
9 25 77 107
0 Answer
import numpy as np
import pandas as pd
data = [12, 13, 15, 16, 14, 11, 19, 24, 28, 25]
arr = np.array(data)
n = len(arr)
sum_3 = np.full(n, np.nan)
sum_5 = np.full(n, np.nan)
sum_3[2:] = arr[:-2] + arr[1:-1] + arr[2:] # 每三项求和
sum_5[4:] = arr[:-4] + arr[1:-3] + arr[2:-2] + arr[3:-1] + arr[4:] # 每五项求和
df = pd.DataFrame({'num': arr, 'sum_3': sum_3, 'sum_5': sum_5})
print(df)
这家伙很懒，什么都没留下...
