aiohttp 3.1.1

Async http client/server framework (asyncio)

Async http client/server framework

Key Features

• Supports both client and server side of HTTP protocol.

• Supports both client and server Web-Sockets out-of-the-box without the Callback Hell.

• Web-server has middlewares and pluggable routing.

Getting started

Client

To retrieve something from the web:

import aiohttp
import asyncio
import async_timeout

async def fetch(session, url):
    async with async_timeout.timeout(10):
        async with session.get(url) as response:
            return await response.text()

async def main():
    async with aiohttp.ClientSession() as session:
        html = await fetch(session, 'http://python.org')
        print(html)

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

Server

This is simple usage example:

from aiohttp import web

async def handle(request):
    name = request.match_info.get('name', "Anonymous")
    text = "Hello, " + name
    return web.Response(text=text)

async def wshandle(request):
    ws = web.WebSocketResponse()
    await ws.prepare(request)

    async for msg in ws:
        if msg.type == web.MsgType.text:
            await ws.send_str("Hello, {}".format(msg.data))
        elif msg.type == web.MsgType.binary:
            await ws.send_bytes(msg.data)
        elif msg.type == web.MsgType.close:
            break

    return ws


app = web.Application()
app.add_routes([web.get('/', handle),
                web.get('/echo', wshandle),
                web.get('/{name}', handle)])

web.run_app(app)

Documentation

https://aiohttp.readthedocs.io/

External links

• Third party libraries

• Built with aiohttp

• Powered by aiohttp

Feel free to make a Pull Request for adding your link to these pages!

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

We support Stack Overflow. Please add aiohttp tag to your question there.

Requirements

• Python >= 3.5.3

• async-timeout

• attrs

• chardet

• multidict

• yarl

Optionally you may install the cChardet and aiodns libraries (highly recommended for sake of speed).

License

aiohttp is offered under the Apache 2 license.

Keepsafe

The aiohttp community would like to thank Keepsafe (https://www.getkeepsafe.com) for it’s support in the early days of the project.

Source code

The latest developer version is available in a github repository: https://github.com/aio-libs/aiohttp

Benchmarks

If you are interested in by efficiency, AsyncIO community maintains a list of benchmarks on the official wiki: https://github.com/python/asyncio/wiki/Benchmarks

Changelog

3.1.1 (2018-03-27)

• Support asynchronous iterators (and asynchronous generators as well) in both client and server API as request / response BODY payloads. (#2802)

3.1.0 (2018-03-21)

Welcome to aiohttp 3.1 release.

This is an incremental release, fully backward compatible with aiohttp 3.0.

But we have added several new features.

The most visible one is app.add_routes() (an alias for existing app.router.add_routes(). The addition is very important because all aiohttp docs now uses app.add_routes() call in code snippets. All your existing code still do register routes / resource without any warning but you’ve got the idea for a favorite way: noisy app.router.add_get() is replaced by app.add_routes().

The library does not make a preference between decorators:

routes = web.RouteTableDef()

@routes.get('/')
async def hello(request):
    return web.Response(text="Hello, world")

app.add_routes(routes)

and route tables as a list:

async def hello(request):
    return web.Response(text="Hello, world")

app.add_routes([web.get('/', hello)])

Both ways are equal, user may decide basing on own code taste.

Also we have a lot of minor features, bug fixes and documentation updates, see below.

Features

• Relax JSON content-type checking in the ClientResponse.json() to allow “application/xxx+json” instead of strict “application/json”. (#2206)

• Bump C HTTP parser to version 2.8 (#2730)

• Accept a coroutine as an application factory in web.run_app and gunicorn worker. (#2739)

• Implement application cleanup context (app.cleanup_ctx property). (#2747)

• Make writer.write_headers a coroutine. (#2762)

• Add tracking signals for getting request/response bodies. (#2767)

• Deprecate ClientResponseError.code in favor of .status to keep similarity with response classes. (#2781)

• Implement app.add_routes() method. (#2787)

• Implement web.static() and RouteTableDef.static() API. (#2795)

• Install a test event loop as default by asyncio.set_event_loop(). The change affects aiohttp test utils but backward compatibility is not broken for 99.99% of use cases. (#2804)

• Refactor ClientResponse constructor: make logically required constructor arguments mandatory, drop _post_init() method. (#2820)

• Use app.add_routes() in server docs everywhere (#2830)

• Websockets refactoring, all websocket writer methods are converted into coroutines. (#2836)

• Provide Content-Range header for Range requests (#2844)

Bugfixes

• Fix websocket client return EofStream. (#2784)

• Fix websocket demo. (#2789)

• Property BaseRequest.http_range now returns a python-like slice when requesting the tail of the range. It’s now indicated by a negative value in range.start rather then in range.stop (#2805)

• Close a connection if an unexpected exception occurs while sending a request (#2827)

• Fix firing DNS tracing events. (#2841)

Improved Documentation

• Change ClientResponse.json() documentation to reflect that it now allows “application/xxx+json” content-types (#2206)

• Document behavior when cchardet detects encodings that are unknown to Python. (#2732)

• Add diagrams for tracing request life style. (#2748)

• Drop removed functionality for passing StreamReader as data at client side. (#2793)