Get by dotted path in Python
Python interview exercise on Dicts & Sets, difficulty 2 of 3. Solve it in the editor beside a worked example, or cold in Interview mode with the example hidden; the tests run the moment you do.
Write deep_get(obj, path, default=None) that follows a dotted path such as "a.b.c" through nested dicts. Return default when a key is missing or something on the way is not a dict. A stored value that is falsy (0, "", False) is still a value.
Each exercise pairs a worked example with a twin problem to solve in a real editor; the tests run the moment you do. Interview mode hides the example: solve it from memory, without the hint or the solution, and it counts as solved cold. Progress is saved in your browser, and in your account if you sign in.