你如何提取一个多维阵列的列？ [英] How do you extract a column from a multi-dimensional array?

问题描述

是否有人知道如何从Python中的多维数组中提取一列？

Does anybody know how to extract a column from a multi-dimensional array in Python?

推荐答案

难道您使用的是<一个href=\"http://docs.scipy.org/doc/numpy/user/basics.indexing.html#indexing-multi-dimensional-arrays\">NumPy阵列？ Python有 模块，但不支持多维数组。普通的Python列表是单维的了。

Could it be that you're using a NumPy array? Python has the array module, but that does not support multi-dimensional arrays. Normal Python lists are single-dimensional too.

不过，如果你有一个简单的二维表是这样的：

However, if you have a simple two-dimensional list like this:

A = [[1,2,3,4],
     [5,6,7,8]]

然后就可以提取一列如下：

then you can extract a column like this:

def column(matrix, i):
    return [row[i] for row in matrix]

提取的第二列（索引1）：

Extracting the second column (index 1):

>>> column(A, 1)
[2, 6]

或者，简单地说：

Or alternatively, simply:

>>> [row[1] for row in A]
[2, 6]

这篇关于你如何提取一个多维阵列的列？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！