如何在最简洁的python中求和多维数组? [英] How would I sum a multi-dimensional array in the most succinct python?

问题描述

与之最接近的是求和列

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:

说我有一个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 ]

在一行中，我如何求和整个2d数组?

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

27

推荐答案

您可以轻松完成

sum(map(sum, my_list))

或者

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

并称其为一日，如果您不希望超过2个维度.请注意，由于使用了map()，第一个解决方案很可能不是最快的解决方案(与执行时间一样).进行基准测试并根据需要进行比较.

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了多维数组，请考虑使用 NumPy 及其出色的数组友好功能.这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)

这将适用于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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