Welcome, guest | Sign In | My Account | Store | Cart

Prime Number Generator in Python (half effcient) (Python recipe) by Captain DeadBones
ActiveState Code (http://code.activestate.com/recipes/578401/)

This is a simple prime number generator in python that I put together for an article I wrote How To Find Prime Numbers In Python. In this one we cut the numbers in half so it is only slightly more efficient than the simplest prime number generator.

Note: There are more efficient ways to do this. Please look at my other recipes.

Python, 28 lines
Download
 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
import sys

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

def main(argv):

	if (len(sys.argv) != 3):
		sys.exit('Usage: prime_numbers2.py <lowest_bound> <upper_bound>')

	low = int(sys.argv[1])
	high = int(sys.argv[2])
	
	if (low == 2):
		print 2, 
	
	if (low % 2 == 0):
		low += 1
		
	for i in range(low,high,2):
		if is_prime(i): 
			print i, 
		
if __name__ == "__main__":
	main(sys.argv[1:])
Tags: prime_generator, prime_number