CODEWITHSUNDEEP
pythonpython-3.xdictionary
Julia Ebert
Julia Ebert

Reputation: 1623

Delete key at arbitrary depth in nested dictionary

My goal is to delete a value from a nested dictionary.

Say I have the dictionary: d = {'a': {'b': {'c': 10, 'd': 4}}}.

I know that I could do: del d['a']['b']['d'].

But I have a list of nested keys, of unknown length. I want to produce the same behavior as above if I have the list ['a', 'b', 'd']. The problem is that I don't know the length of the list of keys to use the above syntax.

For accessing a value with the same input, it's easy:

def dict_get_path(dict_in: Dict, use_path: List):
    # Get the value from the dictionary, where (eg)
    # use_path=['this', 'path', 'deep'] -> dict_in['this']['path']['deep']
    for p in use_path:
        dict_in = dict_in[p]
    return dict_in

But I can't figure out any analogous way to delete an item without re-constructing the whole dictionary.

Upvotes: 1

Views: 278

Answers (1)

Barmar
Barmar

Reputation: 781350

Use the same loop, except stop before the last key. Then use that to delete from the innermost dictionary.

def dict_del_path(dict_in: Dict, use_path: List):
    # Loop over all the keys except last
    for p in use_path[:-1]:
        dict_in = dict_in[p]
    # Delete using last key in path
    del dict_in[use_path[-1]]

Upvotes: 3

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