Skip to main content

Asynchronous `zip` like aggregator for `async for`

Project description

AsyncZip is a simple zip like function working with asynchronous iterables. It look, in many aspects, like asyncio.wait.

Usage

Given n asynchronous iterables, AsyncZip(*aiterables) gives a new asynchronous iterable iterating over all of them. Like asyncio.wait, it’s possible to wait for any iterable to yield something using the option FIRST_COMPLETED, or to wait for all of them using the option ALL_COMPLETED.

class AsyncZip

def __init__(self, *asynchronous_iterables, loop=None, yield_when=FIRST_COMPLETED):
  • asynchronous_iterables: A collection of asynchronous iterables

  • loop: Optional named parameter, to give an specific event loop

  • yield_when: Like return_when from asyncio.wait, FIRST_COMPLETED or ALL_COMPLETED.

FIRST_COMPLETED, ALL_COMPLETED

The two values yield_when can take, FIRST_COMPLETED and ALL_COMPLETED tell, like for asyncio.wait, when AsyncZip should yield. Defaults to FIRST_COMPLETED.

  • FIRST_COMPLETED

Like select, where AsyncZip yields each time any iterable yields, as soon as possible.

  • ALL_COMPLETED

It’s the classical zip mode, where AsyncZip waits for a value for each iterator before yielding them all in a single loop.

Example usage

import asyncio
from asynczip import AsyncZip

class DummyAsyncIterable:
    def __init__(self, items):
        self.items = items

    async def __aiter__(self):
        return self

    async def __anext__(self):
        try:
            return self.items.pop(0)
        except IndexError:
            raise StopAsyncIteration

async def test():
    async for items in AsyncZip(DummyAsyncIterable(list("foo")),
                                DummyAsyncIterable(list("bar"))):
        print(items)

asyncio.get_event_loop().run_until_complete(test())

Gives:

[<Task finished coro=<DummyAsyncIterable.__anext__() done, defined at test.py:11> result='f'>,<Task finished coro=<DummyAsyncIterable.__anext__() done, defined at test.py:11> result='b'>]
[<Task finished coro=<DummyAsyncIterable.__anext__() done, defined at test.py:11> result='o'>, <Task finished coro=<DummyAsyncIterable.__anext__() done, defined at test.py:11> result='a'>]
[<Task finished coro=<DummyAsyncIterable.__anext__() done, defined at test.py:11> result='o'>, <Task finished coro=<DummyAsyncIterable.__anext__() done, defined at test.py:11> result='r'>]

Project details


Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

asynczip-1.0.7.tar.gz (3.4 kB view details)

Uploaded Source

File details

Details for the file asynczip-1.0.7.tar.gz.

File metadata

  • Download URL: asynczip-1.0.7.tar.gz
  • Upload date:
  • Size: 3.4 kB
  • Tags: Source
  • Uploaded using Trusted Publishing? No

File hashes

Hashes for asynczip-1.0.7.tar.gz
Algorithm Hash digest
SHA256 eea2b2375256dce6da2457d79212deb1c7861146238853be6c5c15aa5be8ebfc
MD5 070863ec67dcebb4851ef5cf515e2665
BLAKE2b-256 867f47f404eae0286669a02bd929c220bca6fadf63d38672c935075885b2026a

See more details on using hashes here.

Provenance

Supported by

AWS AWS Cloud computing and Security Sponsor Datadog Datadog Monitoring Fastly Fastly CDN Google Google Download Analytics Microsoft Microsoft PSF Sponsor Pingdom Pingdom Monitoring Sentry Sentry Error logging StatusPage StatusPage Status page