99 problems - python - 35

Determine the prime factors of a given positive integer. Construct a flat list containing the prime factors in ascending order.

def prime_factors(n):
    factor = 2
    while n > 1:
        if n % factor == 0:
            yield factor
            n = n / factor
        else:
            factor += 1

This ended up being simpler and more beautiful than I was expecting. I think I'm falling in love with python all over again. *snif*