merge_dict_deep.py

import copy


def merge_dict_deep(dest, src):
    merged_dict = copy.deepcopy(dest)

    for key in src:
        if key not in dest:
            merged_dict[key] = src[key]
        elif isinstance(dest[key], dict) and isinstance(src[key], dict):
            merged_dict[key] = merge_dict_deep(dest[key], src[key])

    return merged_dict