There isn't any function in the standard library (to my knowledge) that will do it, but there are absolutely modules out there which have such functions. However, its easy enough that you can just write your own function:
def normalize(lst):
s = sum(lst)
return map(lambda x: float(x)/s, lst)
Sample output:
>>> normed = normalize(raw)
>>> normed
[0.25, 0.5, 0.25]