Fix Mobygames score (0.0 ... 10.0 scale) to ES gamelist score (0.0 ... 1.0 scale) in Skyscraper's db.xml file. Skyscraper versions before 3.8.1 did divide by 5 and not by 10.

adjust_mobygames_rating_skyscraper_db_xml.py

#! /usr/bin/env python3

# Fixes Mobygames score (0.0 ... 10.0 scale) to ES gamelist rating (0.0 ... 1.0
# scale) in db.xml. Skyscraper since v2.6.0 (Aug 2018) calculates ES
# gamelist.xml ratings from mobygames score by dividing by 5.0 which result in
# values between 0.0 and 2.0 and not between zero and one. Maybe the
# implementation was right in the beginneing and then the Mobygames API has been
# changed.

# NB: A fixed Skyscraper version can be found at 
# https://github.com/Gemba/skyscraper

# (c) 2023 Gemba @ GitHub. License: MIT

import sys
import xmltodict
from pathlib import Path


def fix_score(row):
    row["#text"] = f'{float(row["#text"]) / 2.0}'
    return row


if __name__ == "__main__":

    if len(sys.argv) != 2 or not Path(sys.argv[1]).exists():
        print(
            "[!] Provide a Skyscraper cache db.xml filename.\n"
            f"    Usage: python3 {sys.argv[0]} <path/to/db-xml-file>\n"
            "    Inputfile will not be altered, a new XML file will be written."
        )
        sys.exit(1)

    db_xml = sys.argv[1]
    db_out_xml = Path(db_xml).parent / "db_score_fixed.xml"

    print(f"[*] Reading '{db_xml}'.")
    with open(db_xml, "rb") as dbxml:
        db_dict = xmltodict.parse(dbxml, force_list=("resource",))

    if not db_dict["resources"]:
        print(f"[-] Empty XML file.")
        sys.exit()

    rows = [
        fix_score(r)
        for r in db_dict["resources"]["resource"]
        if r["@type"] == "rating"
        and r["@source"] == "mobygames"
        and float(r["#text"]) > 1.0
    ]

    if len(rows):
        print(f"[*] Fixed {len(rows)} ratings(s).")
        with open(db_out_xml, "w") as dbxml:
            xmltodict.unparse(db_dict, output=dbxml, pretty=True, indent="    ")
        print(f"[+] Corrected file at '{db_out_xml}'.")
    else:
        print(f"[*] No rows affected. No file written.")