aiohttp 2.3.0a2

Async http client/server framework (asyncio)

Async http client/server framework

Features

• Supports both client and server side of HTTP protocol.

• Supports both client and server Web-Sockets out-of-the-box.

• 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):
    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 wshandler(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.router.add_get('/echo', wshandler)
app.router.add_get('/', handle)
app.router.add_get('/{name}', handle)

web.run_app(app)

Note: examples are written for Python 3.5+ and utilize PEP-492 aka async/await. If you are using Python 3.4 please replace await with yield from and async def with @coroutine e.g.:

async def coro(...):
    ret = await f()

should be replaced by:

@asyncio.coroutine
def coro(...):
    ret = yield from f()

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 >= 3.4.2

• async-timeout

• 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

Changes

2.2.5 (2017-08-03)

• Don’t raise deprecation warning on loop.run_until_complete(client.close()) (#2065)

2.2.4 (2017-08-02)

• Fix issue with synchronous session closing when using ClientSession as an asynchronous context manager. (#2063)

2.2.3 (2017-07-04)

• Fix _CoroGuard for python 3.4

2.2.2 (2017-07-03)

• Allow await session.close() along with yield from session.close()

2.2.1 (2017-07-02)

• Relax yarl requirement to 0.11+

• Backport #2026: session.close is a coroutine (#2029)

2.2.0 (2017-06-20)

• Add doc for add_head, update doc for add_get. (#1944)

• Fixed consecutive calls for Response.write_eof.

• Retain method attributes (e.g. __doc__) when registering synchronous handlers for resources. (#1953)

• Added signal TERM handling in run_app to gracefully exit (#1932)

• Fix websocket issues caused by frame fragmentation. (#1962)

• Raise RuntimeError is you try to set the Content Length and enable chunked encoding at the same time (#1941)

• Small update for unittest_run_loop

• Use CIMultiDict for ClientRequest.skip_auto_headers (#1970)

• Fix wrong startup sequence: test server and run_app() are not raise DeprecationWarning now (#1947)

• Make sure cleanup signal is sent if startup signal has been sent (#1959)

• Fixed server keep-alive handler, could cause 100% cpu utilization (#1955)

• Connection can be destroyed before response get processed if await aiohttp.request(..) is used (#1981)

• MultipartReader does not work with -OO (#1969)

• Fixed ClientPayloadError with blank Content-Encoding header (#1931)

• Support deflate encoding implemented in httpbin.org/deflate (#1918)

• Fix BadStatusLine caused by extra CRLF after POST data (#1792)

• Keep a reference to ClientSession in response object (#1985)

• Deprecate undocumented app.on_loop_available signal (#1978)

2.1.0 (2017-05-26)

• Added support for experimental async-tokio event loop written in Rust https://github.com/PyO3/tokio

• Write to transport \r\n before closing after keepalive timeout, otherwise client can not detect socket disconnection. (#1883)

• Only call loop.close in run_app if the user did not supply a loop. Useful for allowing clients to specify their own cleanup before closing the asyncio loop if they wish to tightly control loop behavior

• Content disposition with semicolon in filename (#917)

• Added request_info to response object and ClientResponseError. (#1733)

• Added history to ClientResponseError. (#1741)

• Allow to disable redirect url re-quoting (#1474)

• Handle RuntimeError from transport (#1790)

• Dropped “%O” in access logger (#1673)

• Added args and kwargs to unittest_run_loop. Useful with other decorators, for example @patch. (#1803)

• Added iter_chunks to response.content object. (#1805)

• Avoid creating TimerContext when there is no timeout to allow compatibility with Tornado. (#1817) (#1180)

• Add proxy_from_env to ClientRequest to read from environment variables. (#1791)

• Add DummyCookieJar helper. (#1830)

• Fix assertion errors in Python 3.4 from noop helper. (#1847)

• Do not unquote + in match_info values (#1816)

• Use Forwarded, X-Forwarded-Scheme and X-Forwarded-Host for better scheme and host resolution. (#1134)

• Fix sub-application middlewares resolution order (#1853)

• Fix applications comparison (#1866)

• Fix static location in index when prefix is used (#1662)

• Make test server more reliable (#1896)

• Extend list of web exceptions, add HTTPUnprocessableEntity, HTTPFailedDependency, HTTPInsufficientStorage status codes (#1920)

2.0.7 (2017-04-12)

• Fix pypi distribution

• Fix exception description (#1807)

• Handle socket error in FileResponse (#1773)

• Cancel websocket heartbeat on close (#1793)

2.0.6 (2017-04-04)

• Keeping blank values for request.post() and multipart.form() (#1765)

• TypeError in data_received of ResponseHandler (#1770)

• Fix web.run_app not to bind to default host-port pair if only socket is passed (#1786)

2.0.5 (2017-03-29)

• Memory leak with aiohttp.request (#1756)

• Disable cleanup closed ssl transports by default.

• Exception in request handling if the server responds before the body is sent (#1761)

2.0.4 (2017-03-27)

• Memory leak with aiohttp.request (#1756)

• Encoding is always UTF-8 in POST data (#1750)

• Do not add “Content-Disposition” header by default (#1755)

2.0.3 (2017-03-24)

• Call https website through proxy will cause error (#1745)

• Fix exception on multipart/form-data post if content-type is not set (#1743)

2.0.2 (2017-03-21)

• Fixed Application.on_loop_available signal (#1739)

• Remove debug code

2.0.1 (2017-03-21)

• Fix allow-head to include name on route (#1737)

• Fixed AttributeError in WebSocketResponse.can_prepare (#1736)

2.0.0 (2017-03-20)

• Added json to ClientSession.request() method (#1726)

• Added session’s raise_for_status parameter, automatically calls raise_for_status() on any request. (#1724)

• response.json() raises ClientReponseError exception if response’s content type does not match (#1723)

  • Cleanup timer and loop handle on any client exception.

• Deprecate loop parameter for Application’s constructor

2.0.0rc1 (2017-03-15)

• Properly handle payload errors (#1710)

• Added ClientWebSocketResponse.get_extra_info() (#1717)

• It is not possible to combine Transfer-Encoding and chunked parameter, same for compress and Content-Encoding (#1655)

• Connector’s limit parameter indicates total concurrent connections. New limit_per_host added, indicates total connections per endpoint. (#1601)

• Use url’s raw_host for name resolution (#1685)

• Change ClientResponse.url to yarl.URL instance (#1654)

• Add max_size parameter to web.Request reading methods (#1133)

• Web Request.post() stores data in temp files (#1469)

• Add the allow_head=True keyword argument for add_get (#1618)

• run_app and the Command Line Interface now support serving over Unix domain sockets for faster inter-process communication.

• run_app now supports passing a preexisting socket object. This can be useful e.g. for socket-based activated applications, when binding of a socket is done by the parent process.

• Implementation for Trailer headers parser is broken (#1619)

• Fix FileResponse to not fall on bad request (range out of file size)

• Fix FileResponse to correct stream video to Chromes

• Deprecate public low-level api (#1657)

• Deprecate encoding parameter for ClientSession.request() method

• Dropped aiohttp.wsgi (#1108)

• Dropped version from ClientSession.request() method

• Dropped websocket version 76 support (#1160)

• Dropped: aiohttp.protocol.HttpPrefixParser (#1590)

• Dropped: Servers response’s .started, .start() and .can_start() method (#1591)

• Dropped: Adding sub app via app.router.add_subapp() is deprecated use app.add_subapp() instead (#1592)

• Dropped: Application.finish() and Application.register_on_finish() (#1602)

• Dropped: web.Request.GET and web.Request.POST

• Dropped: aiohttp.get(), aiohttp.options(), aiohttp.head(), aiohttp.post(), aiohttp.put(), aiohttp.patch(), aiohttp.delete(), and aiohttp.ws_connect() (#1593)

• Dropped: aiohttp.web.WebSocketResponse.receive_msg() (#1605)

• Dropped: ServerHttpProtocol.keep_alive_timeout attribute and keep-alive, keep_alive_on, timeout, log constructor parameters (#1606)

• Dropped: TCPConnector’s` .resolve, .resolved_hosts, .clear_resolved_hosts() attributes and resolve constructor parameter (#1607)

• Dropped ProxyConnector (#1609)