How to input matrix (2D list) in Python?

Question

I tried to create this code to input an m by n matrix. I intended to input [[1,2,3],[4,5,6]] but the code yields [[4,5,6],[4,5,6]. Same things happ

Answer 1

m,n=map(int,input().split()) # m - number of rows; n - number of columns;

matrix = [[int(j) for j in input().split()[:n]] for i in range(m)]

for i in matrix:print(i)

Answer 2

no_of_rows = 3  # For n by n, and even works for n by m but just give no of rows
matrix = [[int(j) for j in input().split()] for i in range(n)]
print(matrix)

Answer 3

This code takes number of row and column from user then takes elements and displays as a matrix.

m = int(input('number of rows, m : '))
n = int(input('number of columns, n : '))
a=[]
for i in range(1,m+1):
  b = []
  print("{0} Row".format(i))
  for j in range(1,n+1):
    b.append(int(input("{0} Column: " .format(j))))
  a.append(b)
print(a)

Answer 4

a = []
b = []

m=input("enter no of rows: ")
n=input("enter no of coloumns: ")

for i in range(n):
     a = []
     for j in range(m):
         a.append(input())
     b.append(a)

Input : 1 2 3 4 5 6 7 8 9

Output : [ ['1', '2', '3'], ['4', '5', '6'], ['7', '8', '9'] ]

Answer 5

If the input is formatted like this,

1 2 3
4 5 6
7 8 9

a one liner can be used

mat = [list(map(int,input().split())) for i in range(row)]

Answer 6

rows, columns = list(map(int,input().split())) #input no. of row and column
b=[]
for i in range(rows):
    a=list(map(int,input().split()))
    b.append(a)
print(b)

input

2 3
1 2 3
4 5 6

output [[1, 2, 3], [4, 5, 6]]