Look at implementation of asyncio (stdlib) 55 # asyncio/futures.py __all__ = ['CancelledError', 'TimeoutError', 'InvalidStateError', 'Future', 'wrap_future'] # asyncio/protocols.py __all__ = ['BaseProtocol', 'Protocol', 'DatagramProtocol', 'SubprocessProtocol'] # asyncio/queues.py __all__ = ['Queue', 'PriorityQueue', 'LifoQueue', 'JoinableQueue', 'QueueFull', 'QueueEmpty'] # asyncio/__init__.py from .futures import * from .protocols import * from .queues import * ... __all__ = ( futures.__all__ + protocols.__all__ + queues.__all__ + ... )