Project Euler 20 sum of digits in 100!

[root@www ~]# python twenty.py
648
[root@www ~]# cat twenty.py
def factorial(n):
if n == 1:
return 1
else:
return n * factorial(n-1)

s = str(factorial(100))
l = [int(s[i]) for i in range(len(s))]
print sum(l)