学校の情報理論の副産物です。整数をできるだけ大きい2つの素数に分解します。

prime_factorization.py

from typing import Tuple

from sympy import sieve


def prime_factorization(n: int) -> Tuple[int, int]:
    if n < 0:
        raise RuntimeError("Invalid number has passed. Please specify number in the range: 1~")

    first_factor = find_greatest_factor(n)
    second_factor = find_greatest_factor(int(n / first_factor))

    if first_factor * second_factor != n:
        raise RuntimeError(f"The number: {n} can not to be divided in two prime numbers.")

    return first_factor, second_factor


def find_greatest_factor(n: int) -> int:
    is_found = False

    for i in reversed(range(2, n)):
        if n % i == 0 and i in sieve:
            is_found = True
            break

    if is_found:
        return i
    else:
        return n


if __name__ == "__main__":
    print("Number?")
    user_input = int(input())

    print(prime_factorization(user_input))