Updating an object inside an array with PyMongo

Question

I am wondering how do you update a nested array with PyMongo/MongoDB by selecting a document(row) and then going into the nested array and selecting a specific object.

{
    "_id"    : "12345",
    "name"   : "John Doe,
    "mylist" : [
         {
            "nested_id" : "1",
            "data1"     : "lorem ipsum",
            "data2"     : "stackoverflow",
            "data3"     : "james bond"
         },
         {
            "nested_id" : "2",
            "data1"     : "lorem ipsum",
            "data2"     : "stackoverflow",
            "data3"     : "james bond"
         },
         {
            ....
         }     
      ]
}

and then lets say you pass a discretionary with the elements you want to update. In this example only update data1 and data3

data = {
   "data1" : "new lorem",
   "data3" : "goldeneye"       
} 

I have tried with the following syntax, but with no success.

db.testing.find_and_modify(
            query={"_id": "12345", 'mylist.nested_id' : "1"},
            update={"$set": {'mylist' : data}})

what it should look like after the update

{
        "_id"    : "12345",
        "name"   : "John Doe,
        "mylist" : [
             {
                "nested_id" : "1",
                "data1"     : "new lorem",
                "data2"     : "stackoverflow",
                "data3"     : "goldeneye"
             },
             {
                "nested_id" : "2",
                "data1"     : "lorem ipsum",
                "data2"     : "stackoverflow",
                "data3"     : "james bond"
             },
             {
                ....
             }     
          ]
    }

Answer 1

Use "dot notation" and the positional operator in the update portion. Also transform your input to match the "dot notation" form for the key representation:

# Transform to "dot notation" on explicit field
for key in data:
    data["mylist.$." + key] = data[key]
    del data[key]

# Basically makes
# { 
#      "mylist.$.data1": "new lorem",
#      "mylist.$.data3": "goldeneye"
# }

db.testing.find_and_modify(
    query = {"_id": "12345", 'mylist.nested_id' : "1"},
    update = { "$set": data }
)

So that will transpose $ to the actual matched element position from the query portion of the update. The matched array element will be updated and using "dot notation" only the mentioned fields will be affected.

Have no idea what "service" is supposed to mean in this context and I am just treating it as a "transcribing error" since you are clearly trying to match an array element in position.

That could be cleaner, but this should give you the general idea.