RSA prime pair bruteforce searcher

rsa_pq_bruteforce.py

#!/usr/bin/env python3
from typing import Optional, List, Generator

def prime_gen(limit: Optional[int]=None) -> Generator[int, None, None]:
    """Generates prime numbers with an optional upper limit"""
    primes = [2]
    n = 3
    
    while limit is None or limit >= n:
        for prime in primes:
            if n % prime == 0:
                break
        else:
            yield primes[-1]
            primes.append(n)
        n += 2

        
def test_pq(n: int):
    """Returns all pairs of primes that can form n via multiplication."""
    results = []
    for first in prime_gen():
        for second in prime_gen():
            if first * second >= n:
                break
                
        if first * second == n:
            results.append((first, second))
            
        if first > n//2:
            break
            
    return results