How can I construct a matrix with 5 rows and 5 columns?

我如何构造一个5行5列的矩阵？

lst = [1,2,3,4,5]

[[float("inf")]*len(lst) for k in range (len(lst))]

gives me [[inf, inf, inf, inf, inf], [inf, inf, inf, inf, inf], [inf, inf, inf, inf, inf], [inf, inf, inf, inf, inf], [inf, inf, inf, inf, inf]]

给我[[inf，inf]，[inf，inf]]

How can I change the parameters so I can get a 5x5 matrix?

如何更改参数才能获得5x5矩阵？

I'm not sure why you are using the lst variable, but what you need is something approaching this:

我不确定您为什么要使用第一个变量，但您需要的是类似以下内容的变量：

def matrix(x,y,initial):
    return [[initial for i in range(x)] for j in range(y)]

Which gives:

这提供了：

> print matrix(5,5,float('inf'))
[[inf, inf, inf, inf, inf], [inf, inf, inf, inf, inf], [inf, inf, inf, inf, inf], [inf, inf, inf, inf, inf], [inf, inf, inf, inf, inf]]

> my_matrix = matrix(2,2,0)
> print my_matrix
[[0, 0], [0, 0]]
> my_matrix[0][2] = 2
> print my_matrix
[[0, 2], [0, 0]]

A matrix in most languages is just a set of nested arrays. If you need anything more than that you might want to make a custom class.

大多数语言中的矩阵只是一组嵌套数组。如果您需要更多的东西，您可能想要创建一个定制类。

What you have already is a 5x5 matrix. Just represented as a list of rows. If you want something that "looks" like a matrix, maybe you'll like numpy:

您已经拥有的是一个5x5矩阵。仅表示为行的列表。如果你想要一个看起来像矩阵的东西，也许你会喜欢NumPy：

>>> import numpy as np
>>> np.full((5, 5), np.inf)
array([[ inf,  inf,  inf,  inf,  inf],
       [ inf,  inf,  inf,  inf,  inf],
       [ inf,  inf,  inf,  inf,  inf],
       [ inf,  inf,  inf,  inf,  inf],
       [ inf,  inf,  inf,  inf,  inf]])

This is Simplest way I Found to Create
5x5 matrix with row values ranging from 0 to 4

这是我发现的创建行值从0到4的5x5矩阵的最简单方法

arr = np.arange(0,5)

arr = np.tile(arr,(5,1))

arr

import numpy as np

将Numpy导入为NP

x = np.arange(0,5).reshape(5,1)

X=np.arange(0，5).重塑(5，1)

print(x)

打印(X)