adding two matrices in python code example

Example 1: addition of two matrices in python

num = [2, 3, 4], [5, 6, 7]
num2 = [8, 9, 10], [11, 12, 13]
num3 = [0, 0, 0], [0, 0, 0]
for i in range(len(num)):
    print(num[i])
for i in range(len(num)):
    print(num2[i])
print()
for i in range (len(num)):
    for j in range(len(num)+1):
        num3[i][j] = num[i][j] + num2[i][j]

for i in range(len(num3)):
    print(num3[i])

Example 2: addition of matrices in python

# Program to add two matrices using list comprehension

X = [[12,7,3],
    [4 ,5,6],
    [7 ,8,9]]

Y = [[5,8,1],
    [6,7,3],
    [4,5,9]]

result = [[X[i][j] + Y[i][j]  for j in range(len(X[0]))] for i in range(len(X))]

for r in result:
   print(r)

Example 3: how to subtract two matrices in python

matrix1 = [[0, 1, 2], 
           [3, 5, 5], 
           [6, 7, 8]]

matrix2 = [[1, 2, 3], 
           [4, 5, 6], 
           [7, 8, 9]]

#output = [[-1, -1, -1], 
		# [-1, 0, -1], 
        # [-1, -1, -1]]

def subtractTheMatrix(matrix1, matrix2):
    matrix1Rows = len(matrix1)
    matrix2Rows = len(matrix2)
    matrix1Col = len(matrix1[0])
    matrix2Col = len(matrix2[0])

    #base case
    if(matrix1Rows != matrix2Rows or matrix1Col != matrix2Col):
        return "ERROR: dimensions of the two arrays must be the same"

    #make a matrix of the same size as matrix 1 and matrix 2
    matrix = []
    rows = []

    for i in range(0, matrix1Rows):
        for j in range(0, matrix2Col):
            rows.append(0)
        matrix.append(rows.copy())
        rows = []

    #loop through the two matricies and the subtraction should be placed in the
    #matrix
    for i in range(0, matrix1Rows):
        for j in range(0, matrix2Col):
            matrix[i][j] = matrix1[i][j] - matrix2[i][j]
            
    return matrix



print(subtractTheMatrix(matrix1, matrix2))