Primes multiprocessing

import time
import sys
from multiprocessing import Pool
import argparse

#Start and end numbers
start_number = 1
end_number = 10000


parser = argparse.ArgumentParser()
parser.add_argument('-e', '--end', default=10000, type=int, help='End Number')
args = parser.parse_args()
end_number = args.end

#Record the test start time
start = time.time()

#Create variable to store the prime numbers and a counter
primes = []

#Loop through each number, then through the factors to identify prime numbers

r = range(start_number, end_number, 1)

def isPrime(num):
    for div_number in range(2, num):
        if num % div_number == 0:
            return False
    return True

with Pool(24) as p:
    primes = [c for c, keep in zip(r, p.map(isPrime, r)) if keep]

'''
for candidate_number in range(start_number, end_number, 1):
    found_prime = True
    for div_number in range(2, candidate_number):
        if candidate_number % div_number == 0:
            found_prime = False
            break
    if found_prime:
        primes.append(candidate_number)
        noPrimes += 1
'''

#Once all numbers have been searched, stop the timer
end = round(time.time() - start, 2)

#Display the results, uncomment the last to list the prime numbers found
print('Find all primes up to: ' + str(end_number))
print('Time elapsed: ' + str(end) + ' seconds')
print('Number of primes found ' + str(len(primes)))
#print(primes)