How to read a matrix in general user format in Python

Question

I want to read a square matrix like this from the console using python:

1 2 3 
2 1 6
5 1 2

I tried using this:

matrix = [[int(input()) for x in range (n)] for y in range(n)]

But here each element can be given line by line and not like a matrix. We can also read it as a single line but how do I read it like above?

Does this answer your question? [How to get multiline input from user](https://stackoverflow.com/questions/30239092/how-to-get-multiline-input-from-user) — Tomerikoo, Dec 03 '19 at 19:00
That seems to be for string inputs given line by line. I want this stored as a list of integer elements — Akhila, Dec 03 '19 at 19:21
@AkhilaRajeev console input *is* string input. You just need to convert it. — John Coleman, Dec 03 '19 at 19:22

score 1 · Accepted Answer · answered Dec 03 '19 at 19:19

1

You can do this with this:

n=3
[list(map(int, input().split(' '))) for y in range(n)]

Input/Output:

1 2 3
2 1 6
5 1 2
Out[50]: [[1, 2, 3], [2, 1, 6], [5, 1, 2]]

answered Dec 03 '19 at 19:19

oppressionslayer

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blhsing · Answer 2 · 2019-12-03T19:42:06.807

1

@oppressionslayer's answer works but accepts only a matrix of a fixed size as defined by n. Since the number of rows is to be equal to the number of columns, you can simply get the number of columns from the first input and stop taking input when the user enters the same number of rows:

l = []
while not l or len(l) < len(l[0]):
    l.append(list(map(int, input().split())))

so that given an input of:

1 2 3 
2 1 6
5 1 2

l would become:

[[1, 2, 3], [2, 1, 6], [5, 1, 2]]

edited Dec 03 '19 at 19:42

answered Dec 03 '19 at 19:20

blhsing

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But that's a one-line input? – Akhila Dec 03 '19 at 19:33
1

Okay. Thank you :) @blhsing – Akhila Dec 03 '19 at 19:40

How to read a matrix in general user format in Python

2 Answers2