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

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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 happen when I input other m by n matrix, the code yields an m by n matrix whose rows are identical.

Perhaps you can help me to find what is wrong with my code.

m = int(input('number of rows, m = '))
n = int(input('number of columns, n = '))
matrix = []; columns = []
# initialize the number of rows
for i in range(0,m):
  matrix += [0]
# initialize the number of columns
for j in range (0,n):
  columns += [0]
# initialize the matrix
for i in range (0,m):
  matrix[i] = columns
for i in range (0,m):
  for j in range (0,n):
    print ('entry in row: ',i+1,' column: ',j+1)
    matrix[i][j] = int(input())
print (matrix)

Take Matrix input from user in Python, It is also used for multidimensional arrays and as we know matrix is a rectangular array, we will use this library for user input matrix. filter_none. edit close. Take Matrix input from user in Python. Matrix is nothing but a rectangular arrangement of data or numbers. In other words, it is a rectangular array of data or numbers. The horizontal entries in a matrix are called as ‘rows’ while the vertical entries are called as ‘columns’.


you can accept a 2D list in python this way ...

simply

arr2d = [[j for j in input().strip()] for i in range(n)] 
# n is no of rows

for characters

n = int(input().strip())
m = int(input().strip())
a = [[0]*n for _ in range(m)]
for i in range(n):
    a[i] = list(input().strip())
print(a)

or

n = int(input().strip())
n = int(input().strip())
a = []
for i in range(n):
    a[i].append(list(input().strip()))
print(a)

for numbers

n = int(input().strip())
m = int(input().strip())
a = [[0]*n for _ in range(m)]
for i in range(n):
    a[i] = [int(j) for j in input().strip().split(" ")]
print(a)

where n is no of elements in columns while m is no of elements in a row.

In pythonic way, this will create a list of list

Two-dimensional lists (arrays) - Learn Python 3, In Python any table can be represented as a list of lists (a list, where each element Say, a program takes on input two-dimensional array in the form of n rows,  Python | Using 2D arrays/lists the right way Python provides many ways to create 2-dimensional lists/arrays. However one must know the differences between these ways because they can create complications in code that can be very difficult to trace out.


Apart from the accepted answer, you can also initialise your rows in the following manner - matrix[i] = [0]*n

Therefore, the following piece of code will work -

m = int(input('number of rows, m = '))
n = int(input('number of columns, n = '))
matrix = []
# initialize the number of rows
for i in range(0,m):
    matrix += [0]
# initialize the matrix
for i in range (0,m):
    matrix[i] = [0]*n
for i in range (0,m):
    for j in range (0,n):
        print ('entry in row: ',i+1,' column: ',j+1)
        matrix[i][j] = int(input())
print (matrix)

How to input a matrix (2D list) in Python, As you know in python everything is dynamic (changes in size of matrix take place at run time), there is no hard and fast rule to input matrix. How To Take 2d Array Input In Python. How to take 'N' number of an input array in Python 3 - Quora Python Exercise: Generates a two-dimensional array Python Exercises, Practice and Solution: Write a Python program which takes two digits m (row) and n (column) as input and generates a two-dimensional array.


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)

How to make a 2D list or matrix in Python and take a input from user , learntechtotech #rakeshroshan #2dlistinpython How to create a 2D list in Python​? How to Duration: 8:50 Posted: Nov 5, 2017 A matrix is a two-dimensional data structure where numbers are arranged into rows and columns. For example: This matrix is a 3x4 (pronounced "three by four") matrix because it has 3 rows and 4 columns. Python doesn't have a built-in type for matrices. However, we can treat list of a list as a matrix.


If your matrix is given in row manner like below, where size is s*s here s=5 5 31 100 65 12 18 10 13 47 157 6 100 113 174 11 33 88 124 41 20 140 99 32 111 41 20

then you can use this

s=int(input())
b=list(map(int,input().split()))
arr=[[b[j+s*i] for j in range(s)]for i in range(s)]

your matrix will be 'arr'

Python 2D List Examples, An array is faster than a list. Array. Python program that uses jagged lists # A jagged list. values = [[10, 20], [30, 40, 50,  We have already tried to explain that a for-loop variable in Python can iterate not only over a range(), but generally over all the elements of any sequence. Sequences in Python are lists and strings (and some other objects that we haven't met yet). Look how you can print a two-dimensional array, using this handy feature of loop for:


Python Exercise: Generates a two-dimensional array, Write a Python program which takes two digits m (row) and n (column) as input and generates a two-dimensional array. The element value in  If you really want a matrix, you might be better off using numpy.Matrix operations in numpy most often use an array type with two dimensions. There are many ways to create a new array; one of the most useful is the zeros function, which takes a shape parameter and returns an array of the given shape, with the values initialized to zero:


Lesson 10 - Multidimensional lists in Python, This tutorial goes over 2d lists and multidimensional arrays in general. It'd be more appropriate to create our own data type (called enumerable) for these  Python | Get a list as input from user We often encounter a situation when we need to take number/string as input from user. In this article, we will see how to get as input a list from the user.


Two-Dimensional Arrays \ Processing.org, A two-dimensional array is really nothing more than an array of arrays (a We can use this type of data structure to encode information about an image. 2D array. Python supports a special "array" from the array module. An integer array is more compact in memory than an integer list. We can create a flattened 2D array. 2D Array. Usage. Sometimes a 2D list is helpful in programs. For a simple or small coordinate system or grid, nested lists can be useful. They are flexible. The syntax is clear.