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Problems with Deleting Elements of Subdictionary in Pymongo MongoDb

I have a problem for several hours and didnt find an answer yet. My Problem is that i want to delete a key/value pair in subdictionary.
Structure is the following in MongoDB :
'_id' : objectId
'title: 'title'
'words': {
'word1' : [pos0,pos1,pos2,pos3],
'word2' : [pos0,pos1,pos2,pos3],
.
.
.
}
When I run this query :
client = pymongo.MongoClient(f"MONGODB_CONNECTION_LINK")
db = client.database
cursor = db['templates'] #OR cursor = db['templates'][index]
query = { 'words': { f'{word}' : f'{pos}' }}
x = cursor.delete_many(query)
and print out the cursor i get the place back where the deleteResult Object is located. Also when i delete them and print out the return, it says that something was deleted.. But when i go to my database its still there.
Index is the object where i want to delete from. Like Index[0] should be the first Object in the database. But when i try to delete with or without Index its the same result.
BTW also tried some other querys but probably not the right one.
Thanks for help guys
[

There were 2 Problems inside my Code:
I didnt access the entries properly according to the Post:
MongoDB - finding entries using a nested dictionary
I saved my Word Values with dots. Therefore i allowed mongodb to store with dots. In this Case its not possible to access the Entries correctly.
Now i just added an new Regex:
regex3 = re.compile(r'[,.]')
re.sub(regex3,'',words.decode_contents()))
I think the Cursor just points to the expected Location of the data. Even if the location exists or not. You dont get back an Error or something like this. Same with the DeleteResult.

JSON issue with MongoDB ObjectId

As you know MongoDB documents has at least one ObjectId named _id. It's not possible to convert a document contains an ObjectId to JSON. currently I have two solutions to convert this document to JSON:
del doc['_id']
or create a new document with a string instance of that field.
What it just works when I know which field contains ObjectId. What to do if I have multiple ObjectId and I don't know what are they?

MongoDB returns a BSON (not a JSON) document, so actually you want to convert a BSON document into JSON document.
Try to take a look into this artickle: https://technobeans.com/2012/09/10/mongodb-convert-bson-to-json/

PyMongo find_one() returns nothing when passed _id as query parameter

I have a single document in my Mongo database:
{"_id" : ObjectId("569bbe3a65193cde93ce7092"),
"categories" : [{_id: 0, "category": "Groceries"},
{_id: 1, "category": "Bills"}, . . .]}
Using PyMongo in my project, I get this result calling find_one():
x = db.collection.find_one({"_id": "ObjectId(\"569bbe3a65193cde93ce7092\")"})
print(x)
// None
Whenever I perform this same query in the Mongo shell, it returns my document. I cannot for the life of me figure out why this is not working. Using find({}) returns the document, so I know PyMongo can see it.
I can call find_one({"categories": {"$exists": True}}) to retrieve the document, and since this will be the only document containing "categories", this will work; however, now I'm just baffled as to why accessing the document by _id is giving me such trouble. Neither escaping the quotes nor quote-wrapping 569bbe3a65193cde93ce7092 has made any difference.

To add to the #Simulant answer, you need to import the ObjectId from the bson.objectid:
from bson.objectid import ObjectId
x = db.collection.find_one({"_id": ObjectId("569bbe3a65193cde93ce7092")})

pass it without the quotes on the content of _id you also need to import ObjectId.
from bson.objectid import ObjectId
{"_id": ObjectId("569bbe3a65193cde93ce7092")}
If you pass it with quotes you are searching for an Object with the String ObjectId("569bbe3a65193cde93ce7092") as ID. But in MongoDB the ID is an Object and not a String. Thats a difference.

To find the _id of document other than during insertion

I have created several documents and inserted into Mongo DB.I am using python for the same . Is there a way where in I can get the _id of a particular record?
I know that we get the _id during insertion. But if i need to use it at a lateral interval is there a way I can get it by say using the find() command?

You can user the projection to get particular field from the document like this
db.collection.find({query},{_id:1}) this will return only _id
http://docs.mongodb.org/manual/reference/method/db.collection.find/

In python, you can use the find_one() method to get the document and access the _id property as following:
def get_id(value):
# Get the document with the record:
document = client.db.collection.find_one({'field': value}, {'_id': True})
return document['_id']

When you insert the record, you can specify the _id value. This has added benefits for when you're using ReplicaSets as well.
from pymongo.objectid import ObjectId
client.db.collection.insert({'_id': ObjectId(), 'key1': value....})
You could store those Ids in a list and use it later on if your requirement for needing the _id occurs immediately after insert.

pymongo saving embedded objectIds, InvalidDocumentError

Using the pymongo driver bare to connect python to mongodb, why is it that using an ObjectId instance as the key for an embedded document raises an InvalidDocument error?
I am trying to link documents using objectids and cant seem to understand why I would want to convert them to strings when the ones created automatically for the driver are ObjectId instances.
item = collection.find({'x':'foo'})
item['otherstuff'] = {pymongo.objectid.ObjectId() : 'data about this link'}
collection.update({'x':'foo'}, item)
bson.errors.InvalidDocument: documents must have only string keys, key was ObjectId('4f0b5d4e764df61c67000000')
In practice the linked ids represent documents that contain questions, and the values in the dictionary here keyed as 'otherstuff' for example would represent this individual document's responses to that particular question.
Is there a reason applying objectids like this won't encode into bson and then fails? Is it impossible to nest ObjectIds within documents like this to cross-reference? Have I misunderstood the purpose of them?

The BSON spec dictates that keys must be strings, so PyMongo is right to reject this as an invalid document (and would be regardless of at what level an ObjectId was used as a key, whether at the top level or in an embedded document). This is necessary, among other reasons, so that the query language can be unambiguous. Imagine you had this document (and that it were a valid BSON document):
{ _id: ...,
"4f0cbe6d7f40d36b24a5c4d7": true,
ObjectId("4f0cbe6d7f40d36b24a5c4d7"): false
}
And then you attempted to query with:
db.foo.find({"4f0cbe6d7f40d36b24a5c4d7": false})
Should this return this document? Should that string be auto-boxed into an ObjectId? How would Mongo know when that can be auto-boxed, and how to disambiguate in cases like this document?
A possible alternative solution to your problem is to have an array of embedded documents like:
{ answers: [
{ answer_id: ObjectId("..."), summary: "Good answer to this question" },
{ answer_id: ObjectId("..."), summary: "Bad answer to this question" }
]
}
This is valid BSON, and will also be indexable more efficiently. If you add an index on answers, you can search efficiently for exact matches on these subdocuments; if you add an index on answers.answer_id, then you can search efficiently by the ObjectId of the answer you're looking for (and so on).