prog13_6.py

import json

name, *scores = input("名前と3科目の得点をカンマ区切りで入れて下さい:").split(",")
score_list = [int(score) for score in scores]
average = round(sum(score_list) / len(score_list), 1)
exam_result = {"name": name, "scores": score_list, "average": average}
with open("exam_result.json", "w", encoding="utf-8") as file_obj:
    json.dump(exam_result, file_obj)

# プログラム13-6（JSONファイルの出力）