Búsqueda por ObjectId en mongodb con pymongo

Necesito buscar un ObjectId con python usando pymongo pero siempre recibo este error. ¿Alguna idea de cómo buscar?

import pymongo from pymongo import MongoClient from pymongo import ObjectId gate = collection.find({'_id': ObjectId(modem["dis_imei"])}) print gate Traceback (most recent call last): File "C:\Users\gerswin\Documents\Proyectos\Demonio py\test.py", line 2, in  import pymongo File "C:\Python27\lib\site-packages\pymongo\__init__.py", line 80, in  from pymongo.connection import Connection File "C:\Python27\lib\site-packages\pymongo\connection.py", line 39, in  from pymongo.mongo_client import MongoClient File "C:\Python27\lib\site-packages\pymongo\mongo_client.py", line 45, in  from pymongo import (auth, File "C:\Python27\lib\site-packages\pymongo\database.py", line 22, in  from pymongo.collection import Collection File "C:\Python27\lib\site-packages\pymongo\collection.py", line 25, in  from pymongo.cursor import Cursor File "C:\Python27\lib\site-packages\pymongo\cursor.py", line 19, in  from bson import RE_TYPE ImportError: cannot import name RE_TYPE 

Yo uso pymongo 2.4.1.

 from bson.objectid import ObjectId [i for i in dbm.neo_nodes.find({"_id": ObjectId(obj_id_to_find)})]