Two ways to update docs in cursor objects with pymongo

I have a collection with:

name weight amount
—————————————-
apple 2 3
banana 2 5
pear 2 5

I want add a column about the total price, which is equal to weight * amount

name weight amount total
—————————————————-
apple 2 3 6
banana 2 5 10
pear 2 5 10

Method 1: collection.find() + update_one()

Method 2: collection.aggregate() with $project, $multiply and $out