program not working

import sys

import random

def selection_sort(A):

for i in range(len(A)):

min_idx = i

for j in range(i+1, len(A)):

if A[min_idx] > A[j]:

min_idx = j

A[i], A[min_idx] = A[min_idx], A[i]

n=int(input("Enter number: "))

arr=[]

for i in range(n):

arr.append(random.randint(1,100))

print ("before sorting array is:")

for i in range(len(arr)):

print ("%d" %arr[i])

selection_sort(arr)

print ("Sorted array is:")

for i in range(len(arr)):

print ("%d" %arr[i]),