How to Clean and Format Data in Python

import json
from pathlib import Path


def load_data(filepath: str) -> dict:
    """Load JSON data from a file."""
    with Path(filepath).open("r", encoding="utf-8") as f:
        return json.load(f)


def clean_records(records: list[dict]) -> list[dict]:
    """Remove empty fields and normalize text to lowercase."""
    cleaned = []
    for record in records:
        filtered = {k: str(v).strip().lower() for k, v in record.items() if v}
        if filtered:
            cleaned.append(filtered)
    return cleaned


def summarize(records: list[dict]) -> dict:
    """Return counts and unique keys across records."""
    keys = set()
    for record in records:
        keys.update(record.keys())
    return {"record_count": len(records), "unique_keys": sorted(keys)}


if __name__ == "__main__":
    raw = load_data("data.json")
    cleaned = clean_records(raw["users"])
    summary = summarize(cleaned)
    print(json.dumps(summary, indent=2))