How delete all keys in a nested dictionary if the key equals a given key

Question

I have a nested dictionary that's updated dynamically so I never know how many levels there are. What I need to do is delete all entries in the dictionary that equal a given key like "command" for example.

I've tried looping through the dict but I found that the number of levels change at runtime so that didn't work. I was thinking that maybe this should use recursion but I would like to avoid that if I can. I have include a sample of a mock dict, what I want is all keys that = command to be removed.

    data = {
        'id': 1,
        'name': 'Option 1',
        'command': do_something,
        'sub_opt': {
            'id': 10,
            'name': 'Sub Option',
            'command': do_something_more,
            'sub_sub_opt': {
                'id': 100,
                'name': 'Sub Sub Option',
                'command': do_something_crazy,
            }
        }
    }

Recursion is the way to go for any nested data structure with unknown depth. Why do you want to avoid it? — Selcuk, Aug 06 '19 at 01:13
Just loops trying to wrap my mind around how to do it recursively. — Daniel Huckson, Aug 06 '19 at 01:19
Another option is to flatten the dictionary - [The 179 point answer here](https://stackoverflow.com/questions/6027558/flatten-nested-dictionaries-compressing-keys) is worth investigation. — DaveStSomeWhere, Aug 06 '19 at 01:23

score 1 · Accepted Answer · answered Aug 06 '19 at 01:27

I know you're trying to avoid recursion, but the code isn't all that bad. Here's an example. (I changed the the values of 'command' keys to strings.)

def delete(data, key):                                                                              
    data.pop(key, None)                                                                             
    for k, v in data.items():                                                                       
        if isinstance(v, dict):                                                                     
            delete(v, key)                                                                          

delete(data, 'command')                                                                             
print(data)

{'id': 1, 'name': 'Option 1', 'command': 'do_something', 'sub_opt': {'id': 10, 'name': 'Sub Option', 'command': 'do_something_more', 'sub_sub_opt': {'id': 100, 'name': 'Sub Sub Option', 'command': 'do_something_crazy'}}}
{'id': 1, 'name': 'Option 1', 'sub_opt': {'id': 10, 'name': 'Sub Option', 'sub_sub_opt': {'id': 100, 'name': 'Sub Sub Option'}}}

How delete all keys in a nested dictionary if the key equals a given key

1 Answers1