python怎么求因数

#coding:utf-8

import math

def generator(count, s):

    if count == 1:

        for i in s:

            yield i

    else:

        for i in s:

            _ = set(s)

            _.remove(i)

            for _ in generator(count-1, _):

                yield _ * 10 + i

primes = [2, 3]

def prime(idx):

    if idx < len(primes):

        return primes[idx]

    new = primes[-1]+2

    while True:

        for i in primes:

            if new % i == 0:

                break

        else:

            primes.append(new)

            break

        new += 2

    return prime(idx)

def probe(number, idx, value=0):

    if value > number:

        return value

    p = prime(idx)

    sqrt = math.sqrt(number)

    while number % p != 0 and sqrt >= p:

        idx += 1

        p = prime(idx)

    if sqrt < p:

        return number

    return probe(number/p, idx, max(p, value))

if __name__ == '__main__':

    _min = 10000000000, 10000000000

    _max = 0, 0

    for number in generator(9, set(range(1, 10))):

        maxfactor = probe(number, 0)

        if maxfactor < _min[0]:

            _min = maxfactor, [number]

        elif maxfactor == _min[0]:

            _min[1].append(number)

        if maxfactor > _max[0]:

            _max = maxfactor, [number]

        elif maxfactor == _max[0]:

            _max[1].append(number)

    print _min

    print _max