Largest palindrome with two three digit factors

#Import Libraries
import numpy as np

#Declare initial empty arrays
num = []
palindromes = []

#Declare function which will reverse strings
def reverse(r):
    return int(str(r)[::-1])

#Generate array of numbers with two three digit factors
for x in range(100,999):
    for y in range(100,999):
        num.append(x*y)

#Isolate palindromes
for x in range(0,len(num)):
    s = (str(num[x]))
    if (num[x]-(reverse(num[x])))==0:
        palindromes.append(num[x])

#Use NumPy to reorder array in ascending order and print the final value in the array.
print(np.sort(palindromes)[(len(palindromes)-1)])