Elegant way to remove fields from nested dictionaries

Question

I had to remove some fields from a dictionary, the keys for those fields are on a list. So I wrote this function:

def delete_keys_from_dict(dict_del, lst_key         


        

Answer 1

Since you already need to loop through every element in the dict, I'd stick with a single loop and just make sure to use a set for looking up the keys to delete

def delete_keys_from_dict(dict_del, the_keys):
    """
    Delete the keys present in the lst_keys from the dictionary.
    Loops recursively over nested dictionaries.
    """
    # make sure the_keys is a set to get O(1) lookups
    if type(the_keys) is not set:
        the_keys = set(the_keys)
    for k,v in dict_del.items():
        if k in the_keys:
            del dict_del[k]
        if isinstance(v, dict):
            delete_keys_from_dict(v, the_keys)
    return dict_del