Prime iterator

prime_iterator.py

import itertools
from typing import Iterator

def sift(ns: Iterator[int]) -> Iterator[int]:
    p = next(ns)
    yield p
    yield from sift(filter(lambda n: n%p != 0, ns))

def primes():
    yield from sift(itertools.count(2))

def first_primes(n: int):
    yield from (p for _, p in zip(range(n), primes()))


def main():
    print(list(first_primes(100)))


if __name__ == "__main__":
    main()