Changelog

Motor 0.2

Changes

Motor 0.2 now requires Tornado 3. However, the previous version, Motor 0.1, is still available for Tornado 2 users.

Motor 0.2 drops Python 2.5 support (since Tornado 3 has dropped it).

All Motor asynchronous methods (except MotorCursor.each()) now return a Future. The callback argument to these methods is now optional. If a callback is passed, it will be executed with the (result, error) of the operation as in Motor 0.1. If no callback is passed, a Future is returned that resolves to the method’s result or error.

The length argument to MotorCursor.to_list() is no longer optional.

The MotorCursor.tail method has been removed. It was complex, diverged from PyMongo’s feature set, and encouraged overuse of MongoDB capped collections as message queues when a purpose-built message queue is more appropriate. An example of tailing a capped collection is provided: Motor Tailable Cursor Example.

MotorClient.is_locked has been removed since calling it from Motor would be bizarre. See “Migration” below for a workaround.

get_gridfs_file() now returns Future instead of accepting a callback.

Migration

motor.Op is deprecated. You can continue to use it, but the simpler syntax yielding a Future is preferred:

document = yield collection.find_one()

Code that uses explicit callbacks with Motor 0.2 works the same as in Motor 0.1:

def callback(document, error):
    if error:
        logging.error("Oh no!")
    else:
        print document

collection.find_one(callback=callback)

Any calls to MotorCursor.to_list() that omitted the length argument must now include it:

result = yield collection.find().to_list(100)

If you relied on MotorCursor.tail, see Motor Tailable Cursor Example for an example of tailing a capped collection with Motor using a coroutine.

If you called MotorClient.is_locked like:

locked = yield motor.Op(client.is_locked)

you should now do:

result = yield client.admin.current_op()
locked = bool(result.get('fsyncLock', None))

Bugfixes

MotorReplicaSetClient.open threw an error if called without a callback.

MotorCursor.to_list ignored SON manipulators. (Thanks to Eren Güven for the report and the fix.)