dict_find_by_path.py

import operator
from functools import reduce


def find(data, element, default=...):
    try:
        return reduce(operator.getitem, element.split('.'), data)
    except KeyError:
        if default is not ...:
            return default
        raise


print(find({'a': {'b': 1}}, 'a.b', 1))
print(find({'a': {'b': 1}}, 'a.c', 2))