Update Variable Depth Dictionary

main.py

import collections
from pprint import pprint

my_dict = {
    'one': {
        'one-one': True,
        'one-two': False,
        'one-three': {
            'one-three-one': True,
        },
    },
    'two': {
        'two-one': True,
    },
}


def update_dict(main, update):
    for k, v in update.items():
        if isinstance(v, collections.Mapping):
            r = update_dict(main.get(k, {}), v)
            main[k] = r
        else:
            main[k] = update[k]
    return main


if __name__ == '__main__':
    print('Original dictionary')
    pprint(my_dict)

    my_update = {
        'one': {
            'one-three': {
                'one-three-two': True,
                'one-three-one': False,
                'one-three-three': 'new',
            }
        }
    }
    print('The update to be applied.')
    pprint(my_update)

    update_dict(my_dict, my_update)
    print('Updated dictionary with new keys and updated values.')
    pprint(my_dict)