Tips For Cleaning Up A Challenge's Answer? Weighted Sum Of Digits

I've been going through some code challenges. And one struck me in particular. CodeAbbey has a Weighted Sum of Digits challenge. And this was my answer. # open and read a file, har

Solution 1:

If using map:

>>>map(lambda d: sum([ (i+1) * int(v) for i,v inenumerate(list(str(d)))]), raw_data)
[6, 19, 14, 114, 137]

Solution 2:

for number in raw_data:
    print(sum(i * int(d) for i, d in enumerate(str(number), 1)))

Solution 3:

This can be done entirely using math operations. Look how the sum is generated, e.g. for 12345146:

                6
              4+6
            1+4+6
          5+1+4+6
        4+5+1+4+6
      3+4+5+1+4+6
    2+3+4+5+1+4+6
+ 1+2+3+4+5+1+4+6

So firs you add last digit, then last and previous, then last, previous and previous etc. until you add all digits. And this can be simply implemented by following algorithm:

raw_data = (6, 19, 64, 6527226, 12345146)  
for d in raw_data:
    wsd = 0
    lst = 0# this is for holding last 'sum row'while d > 0:
        lst = lst + d % 10# append another digit
        wsd += lst
        d //= 10#print wsd
#

On my computer this is about two times faster than algorithms using enumeration and string conversion (I multiplied raw_data 100000 times, thus getting 500000 elements for comparison).