RRFを図解で学ぼう！ - Reciprocal Rank Fusionを、小学3年生でもわかるように説明するよ

from collections import defaultdict


def reciprocal_rank_fusion(rankings, k=60):

    scores = defaultdict(float)


    for ranking in rankings:

        for rank, item in enumerate(ranking, start=1):

            scores[item] += 1 / (k + rank)


    return sorted(

        scores.items(),

        key=lambda x: x[1],

        reverse=True

    )


teacher = ["恐竜ずかん", "宇宙のひみつ", "海の生き物"]

friends = ["宇宙のひみつ", "昆虫大百科", "恐竜ずかん"]

ai = ["恐竜ずかん", "海の生き物", "宇宙のひみつ"]


rankings = [teacher, friends, ai]

result = reciprocal_rank_fusion(rankings, k=10)


for title, score in result:

    print(title, round(score, 3))

出力例

恐竜ずかん 0.259

宇宙のひみつ 0.251

海の生き物 0.160

昆虫大百科 0.083