primesieve3.py

#!/usr/bin/env python3

N = 99999
a = [1,1] + [0]*N
i = 1
j = 0

while i < N:
    if i == j:
        print(i)

    if j > N:
        j = 0
    elif j >= i:
        a[j] = 1
        j += i
    elif a[i]:
        i += 1
    else:
        j = i