core.py

import json
from typing import Any, Dict, List, Union


def load_json(file_path: str) -> Union[Dict[str, Any], List[Any]]:
    """Load JSON data from a file."""
    with open(file_path, 'r') as file:
        return json.load(file)


def save_json(file_path: str, data: Union[Dict[str, Any], List[Any]]) -> None:
    """Save data to a JSON file."""
    with open(file_path, 'w') as file:
        json.dump(data, file, indent=4)


def merge_dicts(dict1: Dict[str, Any], dict2: Dict[str, Any]) -> Dict[str, Any]:
    """Merge two dictionaries recursively."""
    merged = dict1.copy()  # Start with dict1's keys and values
    for key, value in dict2.items():
        if key in merged and isinstance(merged[key], dict) and isinstance(value, dict):
            merged[key] = merge_dicts(merged[key], value)  # Recursive merge
        else:
            merged[key] = value  # If not a dict, overwrite value
    return merged


def flatten_list(nested_list: List[List[Any]]) -> List[Any]:
    """Flatten a nested list into a single list."""
    return [item for sublist in nested_list for item in sublist]


# Example usage
if __name__ == '__main__':
    data1 = load_json('data1.json')
    data2 = load_json('data2.json')
    merged_data = merge_dicts(data1, data2)
    save_json('merged_data.json', merged_data)
    flattened = flatten_list([[1, 2], [3, 4], [5]])
    print(flattened)  # Output: [1, 2, 3, 4, 5]