How to Create a JSON Data Helper in Python

from datetime import datetime
from pathlib import Path
import json


class DataHelper:
    """Simple helper for reading/writing JSON files safely."""

    def __init__(self, base_dir="data"):
        self.base_dir = Path(base_dir)
        self.base_dir.mkdir(exist_ok=True)

    def save(self, filename, data):
        """Save data to a JSON file with timestamp."""
        filepath = self.base_dir / f"{filename}.json"
        record = {
            "saved_at": datetime.now().isoformat(),
            "data": data
        }
        with filepath.open("w") as f:
            json.dump(record, f, indent=2)
        return filepath

    def load(self, filename):
        """Load data from a JSON file; return None if missing."""
        filepath = self.base_dir / f"{filename}.json"
        if not filepath.exists():
            return None
        with filepath.open("r") as f:
            record = json.load(f)
        return record["data"]


if __name__ == "__main__":
    helper = DataHelper()

    # Save example data
    user = {"name": "Alice", "age": 30, "skills": ["python", "cloud"]}
    filepath = helper.save("user", user)
    print(f"Saved to: {filepath}")

    # Load it back
    loaded = helper.load("user")
    print(f"Loaded data: {loaded}")

    # Try loading non-existent file
    missing = helper.load("nonexistent_file")
    print(f"Missing file result: {missing}")