aiohttp 3.4.0

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

async def fetch(session, url):
    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.WSMsgType.text:
            await ws.send_str("Hello, {}".format(msg.data))
        elif msg.type == web.WSMsgType.binary:
            await ws.send_bytes(msg.data)
        elif msg.type == web.WSMsgType.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/

Demos

https://github.com/aio-libs/aiohttp-demos

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

3.4.0 (2018-08-25)

Features

• Add type hints (#3049)

• Add raise_for_status request parameter (#3073)

• Add type hints to HTTP client (#3092)

• Minor server optimizations (#3095)

• Preserve the cause when HTTPException is raised from another exception. (#3096)

• Add close_boundary option in MultipartWriter.write method. Support streaming (#3104)

• Added a remove_slash option to the normalize_path_middleware factory. (#3173)

• The class AbstractRouteDef is importable from aiohttp.web. (#3183)

Bugfixes

• Prevent double closing when client connection is released before the last data_received() callback. (#3031)

• Make redirect with normalize_path_middleware work when using url encoded paths. (#3051)

• Postpone web task creation to connection establishment. (#3052)

• Fix sock_read timeout. (#3053)

• When using a server-request body as the data= argument of a client request, iterate over the content with readany instead of readline to avoid Line too long errors. (#3054)

• fix UrlDispatcher has no attribute add_options, add web.options (#3062)

• correct filename in content-disposition with multipart body (#3064)

• Many HTTP proxies has buggy keepalive support. Let’s not reuse connection but close it after processing every response. (#3070)

• raise 413 “Payload Too Large” rather than raising ValueError in request.post() Add helpful debug message to 413 responses (#3087)

• Fix StreamResponse equality, now that they are MutableMapping objects. (#3100)

• Fix server request objects comparison (#3116)

• Do not hang on 206 Partial Content response with Content-Encoding: gzip (#3123)

• Fix timeout precondition checkers (#3145)

Improved Documentation

• Add a new FAQ entry that clarifies that you should not reuse response objects in middleware functions. (#3020)

• Add FAQ section “Why is creating a ClientSession outside of an event loop dangerous?” (#3072)

• Fix link to Rambler (#3115)

• Fix TCPSite documentation on the Server Reference page. (#3146)

• Fix documentation build configuration file for Windows. (#3147)

• Remove no longer existing lingering_timeout parameter of Application.make_handler from documentation. (#3151)

• Mention that app.make_handler is deprecated, recommend to use runners API instead. (#3157)

Deprecations and Removals

• Drop loop.current_task() from helpers.current_task() (#2826)

• Drop reader parameter from request.multipart(). (#3090)