Flatten dict tech screen

flatten.py

import collections


def flatten(dict_, *, separator='.', raise_on_collision=True):
    flattened = {}
    for key, value in dict_.items():
        if isinstance(value, collections.abc.Mapping):
            tmp_dict = flatten(value)
            for tmp_key, tmp_value in tmp_dict.items():
                tmp_key = separator.join((key, tmp_key))
                if raise_on_collision and tmp_key in flattened:
                    raise ValueError(f"collision on key '{tmp_key}'")
                flattened[tmp_key] = tmp_value
        else:
            if raise_on_collision and key in flattened:
                raise ValueError(f"collision on key '{key}'")
            flattened[key] = value
    return flattened


dict_ = {
    'a': 5,
    'b': 6,
    'c': {
        'f': 9,
        'g': {
            'm': 17,
            'n': 3,
        },
    },
}

print(flatten(dict_))