为什么Python消耗那么大内存？

#!/usr/local/bin/env python



def is_prime(num):

	if num <= 1: return False

	if num != 2 and num % 2 == 0: return False



	to = num / 2 + 1

	for x in range(3, to, 2):

		if num % x == 0: return False

	return True



if __name__ == "__main__":

	primes = []

	for x in range(2, 100):

		if is_prime(x): primes.append(x)

	print(primes)

	

	product = primes[0]

	for i in range(1, len(primes)):

		print("prime: " + str(primes[i]))

		new_prime = product * primes[i] + 1

		if is_prime(new_prime):

			print("new prime: " + str(new_prime))

		else:

			print(str(new_prime) + " is not prime! [error]")

		product *= primes[i]