import timeit
import time
start = time.time()
def prime_factors(n):
    factors = []
    d = 2
    while n > 1:
        while n%d == 0:
            factors.append(d)
            n /= d
        d = d + 1
   
    return factors    

print prime_factors(n)
print "Elapsed Time: %s" % (time.time() - start)

for n in (10**i for i in xrange(2,5)):
    elapsed = timeit.timeit("prime_factors(%d)"%n,\
                            setup="from __main__ import prime_factors",\
                            number=10)
    print "%d took %f"%(n,elapsed)