pymongo update/insert a dict in a document

Question

I want to insert a dict into a document as the value for a field (say v ) if this document does not exist;

db.table.update_one({'k': some_unique_key},
                    {'$set': {'v': {name: 'some_name'},
                    upsert=True) 

Also if the document exists, I want to update the document by updating the dict of the same field ( v ), ie adding one name: value pair to v , I am wondering how to do that.

eg the original document is like,

{'k': some_key, 'v': {'name_a': 'name_a_val'}}

adding one more key:value pair name_b:name_b_val to v is like

{'k': some_key, 'v': {'name_a': 'name_a_val', 'name_b': 'name_b_val'}}

UPDATE

this is the solution I came up with

if not db.table.find_one({'k': some_unique_key}):
    db.table.insert_one({'k': some_unique_key, 'v': {'name_a': 'name_a_val'})
else:
    v_val_dict = db.table.find_one({'k': some_unique_key})['v']

    vat_cache.update_one({'k': some_unique_key},
                     {'$set': {'v': v_val_dict.update({'name_b': 'name_b_val'})}})

I am wondering if there is a better way to do this.

Answer 1

you have to use the dot notation . This will update the nested field named name_a or will create it inside v if it doesn't exist.

coll.update_one({'k': 'some_key'}, 
                {'$set': { 'v.name_a': 'name_a_val'}}, upsert=True)