A common operation in every application is that of updating a single record. For that, we'll use find_one_and_update() provided by PyMongo.
The find_one_and_update() method requires a filter to determine the record to be updated.
The following code tells us how to update a single record using PyMongo:
# Find the record you want to update and save the ID
from pymongo import MongoClient
client = MongoClient('localhost', 27017)
db = client.pythonbicookbook
customers = db.customers
customers.find_one_and_update(
{"first_name": "Bob", "last_name": "Smith"},
{'$set': {'contacted': False,
'updated_at': datetime.datetime.utcnow()}})The first thing we do is create a filter for the update. In this recipe, we look for a record where the first_name field is Bob and the last_name field is Smith. Next, we tell PyMongo about the update operation that is to be applied. Here, we're telling PyMongo to set contacted to False, and to set the updated_at field to the current date and time. We then run the method against the customers collection.
This is the first time we have seen the $set update operator. As you may have guessed, $set sets the value of a field in a document. For the full list of the update operators, visit the MongoDB documentation: https://docs.mongodb.org/manual/reference/operator/update/.
Note
An important note on using find_one_and_update()—I suggest using this method only after you've retrieved the single record that you want to update so that you don't end up updating any other record. For instance, in a web application, if you find a single user's record, you would then use find_one_and_update() to update his or her user record.