如何在最简洁的 python 中对多维数组求和?

2022-01-09 00:00:00 python multidimensional-array sum

问题描述

最接近的是这个汇总列.

所以我会在我的问题中做类似的事情:

So I'll do something similar in my question:

假设我有一个 Python 2D 列表，如下所示:

Say I've a Python 2D list as below:

my_list =  [ [1,2,3,4],
             [2,4,5,6] ]

我可以通过列表理解获得行总数:

I can get the row totals with a list comprehension:

row_totals = [ sum(x) for x in my_list ]

如何在一行中求和整个二维数组?

In one line, how can I sum the entire 2d-array?

27

解决方案

你可以做到这么简单

sum(map(sum, my_list))

或者

sum(sum(x) for x in my_list))

如果您不期望超过 2 个维度，那就收工吧.请注意，由于 map() 的使用，第一个解决方案很可能不是最快的(如执行时间)解决方案.必要时进行基准测试和比较.

and call it a day, if you don't expect more than 2 dimensions. Note that the first solution is most likely not the fastest (as in execution time) solution, due to the usage of map(). Benchmark and compare as necessary.

最后，如果您发现自己使用多维数组，请考虑使用 NumPy 及其优越的数组友好函数.以下是您的问题的简短摘录:

Finally, if you find yourself using multidimensional arrays, consider using NumPy and its superior array-friendly functions. Here's a short excerpt for your problem:

import numpy as np

my_list = np.array([[1,2,3,4], [2,4,5,6]])
np.sum(my_list)

这适用于您的数组可能具有的任意数量的维度.

This would work for any number of dimensions your arrays might have.

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