concurrently 0.3.0

Library helps easy write concurrent executed code blocks

Concurrently

Library helps easy write concurrent executed code blocks.

Quick example:

import asyncio
from concurrently import concurrently


async def amain(loop):
    """
    How to fetch some web pages with concurrently.
    """
    urls = [  # define pages urls
        'http://test/page_1',
        'http://test/page_2',
        'http://test/page_3',
        'http://test/page_4',
    ]
    results = {}

    # immediately run wrapped function concurrent
    # in 2 thread (asyncio coroutines)
    @concurrently(2)
    async def fetch_urls():
        for url in urls:
            page = await fetch_page(url)  # some function for download page
            results[url] = page

    # wait until all concurrent threads finished
    await fetch_urls()
    print(results)


if __name__ == '__main__':
    loop = asyncio.get_event_loop()
    loop.run_until_complete(amain(loop))

Concurrently supports specific different concurrent engines.

Engines

AsyncIOEngine

Default engine for concurrently run code as asyncio coroutines:

from concurrently import concurrently, AsyncIOEngine

...
@concurrently(2, engine=AsyncIOEngine, loop=loop)  # loop is option
async def fetch_urls():
    ...

await fetch_urls()

AsyncIOExecutorEngine

Concurrently run code by asyncio executor:

from concurrent.futures import ThreadPoolExecutor
from concurrently import concurrently, AsyncIOExecutorEngine

...
my_pool = ThreadPoolExecutor()

@concurrently(2, engine=AsyncIOExecutorEngine, loop=loop, executor=my_pool)
def fetch_urls():  # not async def
    ...

await fetch_urls()

If executor is None or not set will using default asyncio executor.

Note: ProcessPoolExecutor is not supported.

ThreadEngine

Concurrently run code in system threads:

from concurrently import concurrently, ThreadEngine

...
@concurrently(2, engine=ThreadEngine)
def fetch_urls():  # not async def
    ...

fetch_urls()  # not await

ThreadPoolEngine

Concurrently run code in system threads by use concurrent.futures.ThreadPoolExecutor:

from concurrently import concurrently, ThreadPoolEngine

...
@concurrently(2, engine=ThreadPoolEngine)
def fetch_urls():
    ...

fetch_urls()

Note: with this engine stop() is not work correctly.

ProcessEngine

Concurrently run code in system process:

from concurrently import concurrently, ProcessEngine

...
@concurrently(2, engine=ProcessEngine)
def fetch_urls():
    ...

fetch_urls()