Who's been dojo herding a lot recently?

cat-me.py

from __future__ import division, print_function

from collections import defaultdict
from operator import itemgetter

get_values = itemgetter(1)

last_few_herders = """
Nicholas
Gautier
Al
Tim
Tom
Tim
Al
Tom
Gautier
Nicholas
Dan
Tim
Gautier
Nicholas
Tom
Nicholas
Tim
""".strip().splitlines()


scores = defaultdict(int)

print('Months ago | Herder     | Weight')
for dmonth, herder in enumerate(reversed(last_few_herders), 1):
    score = 1 / (dmonth)
    print('{:10d} | {:10} | {:5.0f}%'.format(dmonth, herder, 100*score))
    scores[herder] += score

print()
print("Who's been dojo herding a lot recently?")

total = sum(scores.values())
for herder, score in sorted(scores.items(), key=get_values, reverse=True):
    print('{:3.0%} {}'.format((score / total), herder))

feb-output.txt

Months ago | Herder     | Weight
         1 | Tim        |   100%
         2 | Nicholas   |    50%
         3 | Tom        |    33%
         4 | Nicholas   |    25%
         5 | Gautier    |    20%
         6 | Tim        |    17%
         7 | Dan        |    14%
         8 | Nicholas   |    12%
         9 | Gautier    |    11%
        10 | Tom        |    10%
        11 | Al         |     9%
        12 | Tim        |     8%
        13 | Tom        |     8%
        14 | Tim        |     7%
        15 | Al         |     7%
        16 | Gautier    |     6%
        17 | Nicholas   |     6%

Who's been dojo herding a lot recently?
38% Tim
27% Nicholas
15% Tom
11% Gautier
 5% Al
 4% Dan