How to batch delete records using PyMongo

Question

How can we batch delete a number of documents using PyMongo?

If we start off with a list of docs,

docs = list( db.animals.find({'color':'red'}) )

Doing the following does not actually remove anything from the collection!

toRemove = [x['_id'] for x in docs]
db.animals.remove(toRemove)

What is the proper way of batch removing?

Answer 1

Simply use remove the same way you use find.

If the following line returns the records to be removed:

db.animals.find({'color':'red'})

then this will remove them:

db.animals.remove({'color':'red'})

If you already have a list of IDs to remove, you can remove with a filter on the _id, using the $in operator, like this:

db.animals.remove({'_id': {'$in': idsToRemove}})

Answer 2

While some helper method to remove an array of documents may exist that I am unaware of, I would say the best and most explicit way is to use a loop:

for docId in toRemove:
    db.animals.remove({'_id':docId})