sieve.py

'''
    @author: TheRealMentor
    @date: 28/06/2019
'''

import math

def sieve(A):
    if A < 2:
        return []

    allPrimes = [True] * (A+1)
    
    allPrimes[0] = False
    allPrimes[1] = False

    for i in range(2, int(math.sqrt(A))+1):
        if allPrimes[i]:
            for j in range(i*2, A+1, i):
                allPrimes[j] = False

    return [i for i,b in enumerate(allPrimes) if b]

print(sieve(2))
print(sieve(8))
print(sieve(15))