>>> import pymongo
>>> c = pymongo.Connection()
>>> c.foo.authenticate('foo', 'pass')
True
>>> c.foo.foo.insert({'foo': 'bar'})
ObjectId('4ffb5678fba5225a5c58b7ff')
>>> c.foo.foo.find_one()
{u'_id': ObjectId('4ffb5678fba5225a5c58b7ff'), u'foo': u'bar'}
>>> c.foo.foo.insert({'foo': 'bim'}, safe=True)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "pymongo/collection.py", line 306, in insert
    continue_on_error, self.__uuid_subtype), safe)
  File "pymongo/connection.py", line 742, in _send_message
    rv = self.__check_response_to_last_error(response)
  File "pymongo/connection.py", line 678, in __check_response_to_last_error
    helpers._check_command_response(error, self.disconnect)
  File "pymongo/helpers.py", line 129, in _check_command_response
    raise OperationFailure(msg % response["errmsg"])
pymongo.errors.OperationFailure: need to login
>>> for doc in c.foo.foo.find():
...     doc
... 
{u'_id': ObjectId('4ffb5678fba5225a5c58b7ff'), u'foo': u'bar'}
{u'_id': ObjectId('4ffb5687fba5225a5c58b800'), u'foo': u'bim'}