Sieve of Eratosthenes

sieve.py

"""
Implementation of Sieve of Eratosthenes in python.

Algorithm descripition : http://en.wikipedia.org/wiki/Sieve_of_Eratosthenes

"""
def primes(n):
    if n<=2:
        return []
    sieve=[True]*(n+1)
    for x in range(3,int(n**0.5)+1,2):
        for y in range(3,(n//x)+1,2):
            sieve[(x*y)]=False
         
    return [2]+[i for i in range(3,n,2) if sieve[i]]