python - 将 (X, Y) 组合列表相乘

Question

我正在尝试将生成的组合相乘并从中创建一个新列表。

这是我到目前为止所拥有的:

import pandas as pd
import itertools

data1 = [[0.1],[0.2],[0.3],[0.5]]

df = pd.DataFrame(data1, columns = ['weights'])

for x in combinations(df['weights'], 2):
    print(x)

>>>
(0.1, 0.2)
(0.1, 0.3)
(0.1, 0.5)
(0.2, 0.3)
(0.2, 0.5)
(0.3, 0.5)
##I want to make a new list that shows the product of each combinations,
## example: for every (x,y) combo, do x*y and make a new list called z

预期输出应产生一个新列表:

0.02
0.03
0.05
0.06
0.1
0.15

Answer 1

您可以通过简单的列表理解来完成此操作，不必使用itertools:

inlist = [(0.1, 0.2),
(0.1, 0.3),
(0.1, 0.5),
(0.2, 0.3),
(0.2, 0.5),
(0.3, 0.5)]

z = [round(elem[0]*elem[1],2) for elem in inlist]
print(z)

输出:

[0.02, 0.03, 0.05, 0.06, 0.1, 0.15]

但是，如果您想使用 itertools，您可以使用 starmap 来完成。功能:

from itertools import starmap
inlist = [(0.1, 0.2),
(0.1, 0.3),
(0.1, 0.5),
(0.2, 0.3),
(0.2, 0.5),
(0.3, 0.5)]

z = list(starmap(lambda i,j: round(i*j,2), inlist))
print(z)

输出:

[0.02, 0.03, 0.05, 0.06, 0.1, 0.15]