Flatten a dict with comprehensions and a generator.

dict_flatten.py

from typing import Any, Tuple, Generator

SEPARATOR = '.'

def dict_flatten(
    d: dict, parent_key: str = "", sep: str = SEPARATOR
) -> Generator[Tuple[str, Any], None, None]:
    for key, value in d.items():
        if isinstance(value, dict):
            yield from dict_flatten(value, parent_key=f"{parent_key}{key}{sep}")
        else:
            yield (f"{parent_key}{key}", value)

if __name__ == '__main__':
    data = {'apple':{'data':{'price':{'actual':5, 'discounted': 4}}}}
    flat_dict = {key: value for key, value in dict_flatten(data)}
    print(flat_dict)