In the previous article, we have discussed Python Program to Interchange Elements of First and Last Rows in Matrix

Given a matrix and the task is to get the sum of middle row elements and the middle column elements of a given matrix.

**What is a matrix:**

A matrix is a rectangular sequence of numbers divided into columns and rows. A matrix element or entry is a number that appears in a matrix.

**Example:**

Above is the matrix which contains 5 rows and 4 columns and having elements from 1 to 20.

In this order, the dimensions of a matrix indicate the number of rows and columns.

Here as there are 5 rows and 4 columns it is called a 5*4 matrix.

**Examples:**

**Example1:**

**Input:**

Given Matrix : 4 2 0 4 2 3 5 6 9

**Output:**

The sum of middle row elements of the above given matrix = 9 The sum of middle column elements of the above given matrix = 10

**Example2:**

**Input:**

Given Matrix : 0 1 3 4 5 6 8 2 1

**Output:**

The sum of middle row elements of the above given matrix = 15 The sum of middle column elements of the above given matrix = 8

## Program for Sum of Middle Row and Column in Matrix in Python

Below are the ways to get the sum of middle row elements and the middle column elements of a given matrix in python:

### Method #1: Using For Loop (Static Input)

**Approach:**

- Give the matrix as static input and store it in a variable.
- Calculate the number of rows of the given matrix by calculating the length of the nested list using the len() function and store it in a variable mtrxrows.
- Calculate the number of columns of the given matrix by calculating the length of the first list in the nested list using the len() function and store it in a variable mtrxcolums.
- Take a variable to say
**middlrow_sum**and initialize its value to 0. - Take a variable to say
**middlcol_sum**and initialize its value to 0. - Loop till the given number of rows using the For loop.
- Inside the for loop, add mtrx[mtrxrows // 2][itr] to the above-initialized
**middlrow_sum**where itr is the iterator value of the for loop. - Print the sum of the middle row elements of the given matrix.
- Loop till the given number of rows using the For loop.
- Inside the for loop, add mtrx[itr][mtrxrows // 2] to the above-initialized
**middlcol_sum**where itr is the iterator value of the for loop. - Print the sum of the middle column elements of the given matrix.
- The Exit of the Program.

**Below is the implementation:**

# Give the matrix as static input and store it in a variable. mtrx = [[4, 2, 0], [4, 2, 3], [5, 6, 9]] # Calculate the number of rows of the given matrix by # calculating the length of the nested list using the len() function # and store it in a variable mtrxrows. mtrxrows = len(mtrx) # Calculate the number of columns of the given matrix by # calculating the length of the first list in the nested list # using the len() function and store it in a variable mtrxcols. mtrxcols = len(mtrx[0]) # Take a variable to say middlrow_sum and initialize its value to 0. middlrow_sum = 0 # Take a variable to say middlcol_sum and initialize its value to 0. middlcol_sum = 0 # Loop till the given number of rows using the For loop. for itr in range(mtrxrows): # Inside the for loop, add mtrx[mtrxrows // 2][itr] to the above-initialized middlrow_sum # where itr is the iterator value of the for loop. middlrow_sum += mtrx[mtrxrows // 2][itr] # Print the sum of the middle row elements of the given matrix. print("The sum of middle row elements of the above given matrix = ", middlrow_sum) # Loop till the given number of rows using the For loop. for itr in range(mtrxrows): # Inside the for loop, add mtrx[itr][mtrxrows // 2] to the above-initialized middlcol_sum # where itr is the iterator value of the for loop. middlcol_sum += mtrx[itr][mtrxrows // 2] # Print the sum of the middle column elements of the given matrix. print("The sum of middle column elements of the above given matrix = ", middlcol_sum)

**Output:**

The sum of middle row elements of the above given matrix = 9 The sum of middle column elements of the above given matrix = 10

### Method #2: Using For loop (User Input)

**Approach:**

- Give the number of rows of the matrix as user input using the int(input()) function and store it in a variable.
- Give the number of columns of the matrix as user input using the int(input()) function and store it in another variable.
- Take a list and initialize it with an empty value using [] or list() to say
**gvnmatrix**. - Loop till the given number of rows using the For loop
- Inside the For loop, Give all the row elements of the given Matrix as a list using the list(),map(),int(),split() functions and store it in a variable.
- Add the above row elements list to
**gvnmatrix**using the append() function. - Take a variable to say
**middlrow_sum**and initialize its value to 0. - Take a variable to say
**middlcol_sum**and initialize its value to 0. - Loop till the given number of rows using the For loop.
- Inside the for loop, add mtrx[mtrxrows // 2][itr] to the above-initialized
**middlrow_sum**where itr is the iterator value of the for loop. - Print the sum of the middle row elements of the given matrix.
- Loop till the given number of rows using the For loop.
- Inside the for loop, add mtrx[itr][mtrxrows // 2] to the above-initialized
**middlcol_sum**where itr is the iterator value of the for loop. - Print the sum of the middle column elements of the given matrix.
- The Exit of the Program.

**Below is the implementation:**

# Give the number of rows of the matrix as user input using the int(input()) function # and store it in a variable. mtrxrows = int(input('Enter some random number of rows of the matrix = ')) # Give the number of columns of the matrix as user input using the int(input()) function # and store it in another variable. mtrxcols = int(input('Enter some random number of columns of the matrix = ')) # Take a list and initialize it with an empty value using [] or list() to say gvnmatrix. mtrx = [] # Loop till the given number of rows using the For loop for n in range(mtrxrows): # Inside the For loop, Give all the row elements of the given Matrix as a list using # the list(),map(),int(),split() functions and store it in a variable. l = list(map(int, input( 'Enter {'+str(mtrxcols)+'} elements of row {'+str(n+1)+'} separated by spaces = ').split())) # Add the above row elements list to gvnmatrix using the append() function. mtrx.append(l) # Take a variable to say middlrow_sum and initialize its value to 0. middlrow_sum = 0 # Take a variable to say middlcol_sum and initialize its value to 0. middlcol_sum = 0 # Loop till the given number of rows using the For loop. for itr in range(mtrxrows): # Inside the for loop, add mtrx[mtrxrows // 2][itr] to the above-initialized middlrow_sum # where itr is the iterator value of the for loop. middlrow_sum += mtrx[mtrxrows // 2][itr] # Print the sum of the middle row elements of the given matrix. print("The sum of middle row elements of the above given matrix = ", middlrow_sum) # Loop till the given number of rows using the For loop. for itr in range(mtrxrows): # Inside the for loop, add mtrx[itr][mtrxrows // 2] to the above-initialized middlcol_sum # where itr is the iterator value of the for loop. middlcol_sum += mtrx[itr][mtrxrows // 2] # Print the sum of the middle column elements of the given matrix. print("The sum of middle column elements of the above given matrix = ", middlcol_sum)

**Output:**

Enter some random number of rows of the matrix = 3 Enter some random number of columns of the matrix = 3 Enter {3} elements of row {1} separated by spaces = 0 1 3 Enter {3} elements of row {2} separated by spaces = 4 5 6 Enter {3} elements of row {3} separated by spaces = 8 2 1 The sum of middle row elements of the above given matrix = 15 The sum of middle column elements of the above given matrix = 8

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