janus 0.5.0

Mixed sync-async queue to interoperate between asyncio tasks and classic threads

Mixed sync-async queue, supposed to be used for communicating between classic synchronous (threaded) code and asynchronous (in terms of asyncio) one.

Like Janus god the queue object from the library has two faces: synchronous and asynchronous interface.

Synchronous is fully compatible with standard queue, asynchronous one follows asyncio queue design.

Usage example (Python 3.7+)

import asyncio
import janus


def threaded(sync_q):
    for i in range(100):
        sync_q.put(i)
    sync_q.join()


async def async_coro(async_q):
    for i in range(100):
        val = await async_q.get()
        assert val == i
        async_q.task_done()


async def main():
    queue = janus.Queue()
    loop = asyncio.get_running_loop()
    fut = loop.run_in_executor(None, threaded, queue.sync_q)
    await async_coro(queue.async_q)
    await fut
    queue.close()
    await queue.wait_closed()


asyncio.run(main())

Usage example (Python 3.5 and 3.6)

import asyncio
import janus

loop = asyncio.get_event_loop()


def threaded(sync_q):
    for i in range(100):
        sync_q.put(i)
    sync_q.join()


async def async_coro(async_q):
    for i in range(100):
        val = await async_q.get()
        assert val == i
        async_q.task_done()


async def main():
    queue = janus.Queue()
    fut = loop.run_in_executor(None, threaded, queue.sync_q)
    await async_coro(queue.async_q)
    await fut
    queue.close()
    await queue.wait_closed()

try:
    loop.run_until_complete(main())
finally:
    loop.close()

Communication channels

aio-libs google group: https://groups.google.com/forum/#!forum/aio-libs

Feel free to post your questions and ideas here.

gitter chat https://gitter.im/aio-libs/Lobby

License

janus library is offered under Apache 2 license.

Thanks

The library development is sponsored by DataRobot (https://datarobot.com)

Changes

0.5.0 (2020-04-23)

• Remove explicit loop arguments and forbid creating queues outside event loops #246

0.4.0 (2018-07-28)

• Add py.typed macro #89

• Drop python 3.4 support and fix minimal version python3.5.3 #88

• Add property with that indicates if queue is closed #86

0.3.2 (2018-07-06)

• Fixed python 3.7 support #97

0.3.1 (2018-01-30)

• Fixed bug with join() in case tasks are added by sync_q.put() #75

0.3.0 (2017-02-21)

• Expose unfinished_tasks property #34

0.2.4 (2016-12-05)

• Restore tarball deploying

0.2.3 (2016-07-12)

• Fix exception type

0.2.2 (2016-07-11)

• Update asyncio.async() to use asyncio.ensure_future() #6

0.2.1 (2016-03-24)

• Fix python setup.py test command #4

0.2.0 (2015-09-20)

• Support Python 3.5

0.1.5 (2015-07-24)

• Use loop.time() instead of time.monotonic()

0.1.1 (2015-06-12)

• Fix some typos in README and setup.py

• Add addtional checks for loop closing

• Mention DataRobot

0.1.0 (2015-06-11)

• Initial release