import json meta = json.load(open("metadata.json", "r", encoding="utf-8")) concepts = json.load(open("concepts.json", "r", encoding="utf-8")) for country in concepts: if not country in meta: meta[country] = dict() for language in concepts[country]: if language not in meta[country]: meta[country][language] = meta["USA"]["English"] with open("metadata.json", "w", encoding="utf-8") as f: json.dump(meta, f, indent=2)