1) > db.test.find()

{ "_id" : ObjectId("4e04e3d79c57c1b8fe3830af"), "v" : 11 }

2) > db.test.findAndModify({query: {}, update: {'$inc': {v: 1}}, new: true})

{ "_id" : ObjectId("4e04e3d79c57c1b8fe3830af"), "v" : 12 }

3) > db.test.findAndModify({query: {}, update: {'$inc': {v: 1}}, new: true, fields: ['v']})

{ "_id" : ObjectId("4e04e3d79c57c1b8fe3830af") }

Output of 3) should contain the 'v' field.

Same thing with the Python driver; with new=False and with multiple fields.