如何在pymongo文档中查看更新的布尔值？

Question

I am trying to listen for an update to a collection using pymongo 3.6.1 .

The collection gets updated with a document that looks something like this:

{"End_Word":"bit","Success":true,"Score":1,"Term_Index":5}

Where if the key Success gets updated to true in any of the documents a def dosomething() gets called.

The mongodb api documentation shows this example, as a first step:

with db.collection.watch() as stream:
    for change in stream:
        print(change)

In attempting to replicate this I am getting a OperationFailure: Unrecognized pipeline stage name: '$changeStream' error. When researching other's with similar issues on stack The answer was connection driver versions. I don't think this is the case here:

Code:

db_name = 'mapstore'
coll_name = 'oxygen'

MONGO_DB_DRIVER = pymongo atlas M2 instance driver
conn = pymongo.MongoClient(MONGO_DB_DRIVER)
db = conn[db_name]
print(db.collection_names())

Update:

I also looked in these places

How to listen for changes to a MongoDB collection? https://docs.mongodb.com/master/changeStreams/

What is the right approach?

Answer 1

The below error

OperationFailure: Unrecognized pipeline stage name: '$changeStream'

Indicates that your Mongodb server is below 3.6.0 and that is why it doesn't recognize this command. Even though you have latest client, doesn't change how the server behaves