Python: Read a matrix from console and print the sum for each column

Last update on April 19 2025 13:02:11 (UTC/GMT +8 hours)

Sum Matrix Columns from Console Input

Write a Python program to read a matrix from the console and print the sum for each column. As input from the user, accept matrix rows, columns, and elements separated by a space (each row).

Visual Presentation:

Sample Solution:

Python Code:

# Prompt the user to input the number of rows for the matrix
rows = int(input("Input rows: "))

# Prompt the user to input the number of columns for the matrix
columns = int(input("Input columns: "))

# Create a 2D matrix filled with zeros using list comprehensions based on the number of rows and columns
matrix = [[0]*columns for row in range(rows)]

# Prompt the user to input the elements for each row in the matrix
print('Input number of elements in a row (1, 2, 3): ')
for row in range(rows):
    # Read a line of space-separated integers and convert them to a list of integers
    lines = list(map(int, input().split()))
    for column in range(columns):
        # Populate the matrix with the input elements
        matrix[row][column] = lines[column]

# Create a list 'sum' initialized with zeros to store the sum for each column
sum = [0]*columns

# Print a message indicating the calculation of the sum for each column
print("Sum for each column:")

# Iterate over each column
for column in range(columns):
    # Calculate the sum of the elements in the current column by iterating through the rows
    for row in range(rows):
        sum[column] += matrix[row][column]
    
    # Print the sum for the current column followed by a space
    print((sum[column]), ' ', end = '')

Sample Output:

Input rows:  2
Input columns:  2
Input number of elements in a row (1, 2, 3): 
 1 2
 3 4
sum for each column:
4  6 

Flowchart:

For more Practice: Solve these Related Problems:

• Write a Python program to sum all rows in a matrix.
• Write a Python program to compute the sum of matrix diagonals.
• Write a Python program to find the largest sum among matrix columns.
• Write a Python program to calculate row-wise and column-wise sums of a matrix.

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Next: Write a Python program to read a square matrix from console and print the sum of matrix primary diagonal. Accept the size of the square matrix and elements for each column separated with a space (for every row) as input from the user.

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