python:整数分解成质因数乘积形式

def (x):#判断一个数是不是质数
    for i in range(2, x - 1):
        if (x % i == 0):
            return 0
        else:
            continue
    return 1
def fen(x):#将输入数字作因数分解,得到质因数和剩余值
    for i in range(2, x - 1):
        if (x % i == 0):
            if (ju(i) == 1):
                return i, x / i
    return 1, x
k = input()
print k, '=',
cheng, yu = fen(k)
while (cheng != 1):
    print cheng, '*',
    cheng, yu = fen(yu)
print yu