How to exchange columns of a matrix in python

I am trying to exchange the columns of a matrix in Python the column with the smallest prime with the column with the bigger prime of the given matrix

I was trying

def swapcol(matriz,col1,col2):
    for i in range(len(matriz)):
        aux = matriz[i][col1]
        matriz[i][col1] = matriz[i][col2]
        matriz[i][col2] = aux
    


def esprimo(n):
    m = 0
    for i in range(1,n+1):
        if n % i == 0:
            m += 1
    if m == 2:
        return True
    else:
        return False

def leermatrix(matrix,r,c):
    for i in range(r):
        a = []
        for j in range(c):
            a.append(int(input("enter element: ")))
        matrix.append(a)

r = int(input("enter the number of rows: "))
c = int(input("enter the number of columns: "))
matrix = []


leermatrix(matrix,r,c)

mayp = matrix[0][0]
menp = matrix[0][0]
colmen = 0
colmay = 0

for j in range(c):
    for i in range(r):
        if esprimo(matrix[i][j]) and matrix[i][j] > mayp:
            mayp = matrix[i][j]
            colmay = j
        if esprimo(matrix[i][j]) and esprimo(matrix[i][j]) < menp:
            menp = matrix[i][j]
            colmen = j



swapcol(matrix,colmay,colmen)
print(matrix)

the output I get is the same matrix that I put, what did I get wrong?

>Solution :

I made a few modifications to your code.

• The condition esprimo(matrix[i][j]) and matrix[i][j] > mayp: should be replaced with matrix[i][j] > mayp
• The condition esprimo(matrix[i][j]) and esprimo(matrix[i][j]) < menp should be replaced with matrix[i][j] < menp and matrix[i][j] > 1
• Initialized mayp with -1 and menp with positive infinity to ensure they are updated correctly.
• Also there’s no need to swap columns if the colmay and colmen values are the same

Here’s your solution:

def swapcol(matriz, col1, col2):
    for i in range(len(matriz)):
        aux = matriz[i][col1]
        matriz[i][col1] = matriz[i][col2]
        matriz[i][col2] = aux
    return matriz

def esprimo(n):
    if n <= 1:
        return False
    for i in range(2, int(n**0.5) + 1):
        if n % i == 0:
            return False
    return True

def leermatrix(matrix, r, c):
    for i in range(r):
        a = []
        for j in range(c):
            a.append(int(input("Enter element: ")))
        matrix.append(a)

r = int(input("Enter the number of rows: "))
c = int(input("Enter the number of columns: "))
matrix = []

leermatrix(matrix, r, c)

print("Original matrix:")
for row in matrix:
    print(row)


mayp = -1
menp = float('inf')
colmen = 0
colmay = 0

for j in range(c):
    for i in range(r):
        if esprimo(matrix[i][j]):
            if matrix[i][j] > mayp:
                mayp = matrix[i][j]
                colmay = j
            if matrix[i][j] < menp and matrix[i][j] > 1:
                menp = matrix[i][j]
                colmen = j

if colmay != colmen:
    matriz = swapcol(matrix, colmay, colmen)

print("\nMatrix after swapping columns:")
for row in matriz:
    print(row)

Output:

Original matrix:
[1, 2, 3]
[4, 5, 6]
[7, 8, 9]

Matrix after swapping columns:
[2, 1, 3]
[5, 4, 6]
[8, 7, 9]