Itertools Groupby遍历不同的列 [英] Itertools Groupby looping over different columns

问题描述

试图在Python中执行条件求和积.简化的想法如下:

'm trying to do a conditional sum-product in Python. The simplified idea is as follows:

A = [1 1 2 3 3 3]
B = [0.50 0.25 0.99 0.80 0.70 0.20]

我希望将其作为输出

Total1 = 0.50*1 + 0.25*1
Total2 = 0.99*2
Total3 = 0.80*3 + 0.70*3 + 0.20*3 

感谢这里的人们的支持，这一部分工作了！

Thanks to the support by people over here, this part worked out!

我要添加的下一个功能是能够针对不同的列"B"(例如B1，​​B2，B3 ...)(具有不同的值)进行计算. 这些存储在Excel中，我用openpyxl将它们读出到不同的列表中(可能更有效...) 这意味着B1/B2/...中的值与A中的相应值相对应.

Next function I like to add, is being able to calculate this for different columns 'B' (say B1, B2, B3, ...) (with different values). These are stored in Excel and I read them out to different lists with openpyxl (can probably be more efficient...) This means the values in B1/B2/... are corresponding with the respective values in A.

number = -1
j = 0
for col in ws.iter_cols():
    if col[3].value == "fast" :
        number = j
    j+=1

B1 = [row[number].value for row in ws.iter_rows(min_row=5, max_row=63332) ]
B1_float = [float(i) for i in B1]

是否可以执行将此脚本划分为不同的组合(A& B1/A& B2/A& B3/...)并将其存储在矩阵中? (或Excel文件)

Is there a way to perform this script to different combinations (A&B1 / A&B2 / A&B3 / ...) and store them in a matrix? (or excel file)

我希望我的意思很清楚，否则请让我知道！

I hope it's clear what I mean, if not, let me know!

推荐答案

您似乎在问两个问题:

1. 根据单独列表中的组计算产品总和
2. 将这些结果写入Excel文件

由于这些是完全不同的问题，因此我将解决第一个问题，并参考第二个问题.

As these are quite different problems, I will address the first and refer to references on the second.

import operator as op
import itertools as it
import functools as ft


A = [1, 1, 2, 3, 3, 3]
B = [0.5, 0.25, 0.99, 0.8, 0.7, 0.2]

groups = [list(g) for k, g in it.groupby(zip(A, B), op.itemgetter(0))]
groups
# [[(1, 0.5), (1, 0.25)], [(2, 0.99)], [(3, 0.8), (3, 0.7), (3, 0.2)]]

在这里，我们压缩数据列并根据列表A将它们分组.现在，我们可以将适当的运算符应用于groups中的每个可迭代项.

Here we zip the columns of data and group them according to list A. Now we are able to apply the appropriate operators to each iterable in groups.

[sum(ft.reduce(op.mul, i) for i in sub) for sub in groups]
# [0.75, 1.98, 5.1]

关于将数据写入Excel的方法，有几个Python库可用，每个库都包含有关文档怎么做.

As for writing data to Excel, there are several Python libraries available, each with documentation on how to do so.

这篇关于Itertools Groupby遍历不同的列的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！