Generate prime numbers up to N using the Sieve of Eratosthenes

primes.py

'''
Get all primes till N (using Sieve of Eratosthenes)

The MIT License (MIT)
Copyright (c) 2016 Suhas S G <[email protected]>
'''
import math


def primes(n):
    s, s[:2] = [True] * n, [False, False]
    sqrtn = int(math.sqrt(n) + 1)
    for i in range(sqrtn):
        if s[i]:
            for j in range(i*i, n+1, i):
                s[j] = False
    return [i for i, p in enumerate(s) if p]