aiohttp 4.0.0a0

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 and avoids Callback Hell.

• Provides Web-server with middlewares and pluggable routing.

Getting started

Client

To get 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

An example using a simple server:

# examples/server_simple.py
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 its 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 efficiency, the AsyncIO community maintains a list of benchmarks on the official wiki: https://github.com/python/asyncio/wiki/Benchmarks

Changelog

3.5.2 (2019-01-08)

Features

• FileResponse from web_fileresponse.py uses a ThreadPoolExecutor to work with files asynchronously. I/O based payloads from payload.py uses a ThreadPoolExecutor to work with I/O objects asynchronously. #3313

• Internal Server Errors in plain text if the browser does not support HTML. #3483

Bugfixes

• Preserve MultipartWriter parts headers on write.

  Refactor the way how Payload.headers are handled. Payload instances now always have headers and Content-Type defined.

  Fix Payload Content-Disposition header reset after initial creation. #3035

• Log suppressed exceptions in GunicornWebWorker. #3464

• Remove wildcard imports. #3468

• Use the same task for app initialization and web server handling in gunicorn workers. It allows to use Python3.7 context vars smoothly. #3471

• Fix handling of chunked+gzipped response when first chunk does not give uncompressed data #3477

• Replace collections.MutableMapping with collections.abc.MutableMapping to avoid a deprecation warning. #3480

• Payload.size type annotation changed from Optional[float] to Optional[int]. #3484

• Ignore done tasks when cancels pending activities on web.run_app finalization. #3497

Improved Documentation

• Add documentation for aiohttp.web.HTTPException. #3490

Misc

• #3487

---

3.5.1 (2018-12-24)

• Fix a regression about ClientSession._requote_redirect_url modification in debug mode.

3.5.0 (2018-12-22)

Features

• The library type annotations are checked in strict mode now.

• Add support for setting cookies for individual request (#2387)

• Application.add_domain implementation (#2809)

• The default app in the request returned by test_utils.make_mocked_request can now have objects assigned to it and retrieved using the [] operator. (#3174)

• Make request.url accessible when transport is closed. (#3177)

• Add zlib_executor_size argument to Response constructor to allow compression to run in a background executor to avoid blocking the main thread and potentially triggering health check failures. (#3205)

• Enable users to set ClientTimeout in aiohttp.request (#3213)

• Don’t raise a warning if NETRC environment variable is not set and ~/.netrc file doesn’t exist. (#3267)

• Add default logging handler to web.run_app

  If the Application.debug flag is set and the default logger aiohttp.access is used, access logs will now be output using a stderr StreamHandler if no handlers are attached. Furthermore, if the default logger has no log level set, the log level will be set to DEBUG. (#3324)

• Add method argument to session.ws_connect().

  Sometimes server API requires a different HTTP method for WebSocket connection establishment.

  For example, Docker exec needs POST. (#3378)

• Create a task per request handling. (#3406)

Bugfixes

• Enable passing access_log_class via handler_args (#3158)

• Return empty bytes with end-of-chunk marker in empty stream reader. (#3186)

• Accept CIMultiDictProxy instances for headers argument in web.Response constructor. (#3207)

• Don’t uppercase HTTP method in parser (#3233)

• Make method match regexp RFC-7230 compliant (#3235)

• Add app.pre_frozen state to properly handle startup signals in sub-applications. (#3237)

• Enhanced parsing and validation of helpers.BasicAuth.decode. (#3239)

• Change imports from collections module in preparation for 3.8. (#3258)

• Ensure Host header is added first to ClientRequest to better replicate browser (#3265)

• Fix forward compatibility with Python 3.8: importing ABCs directly from the collections module will not be supported anymore. (#3273)

• Keep the query string by normalize_path_middleware. (#3278)

• Fix missing parameter raise_for_status for aiohttp.request() (#3290)

• Bracket IPv6 addresses in the HOST header (#3304)

• Fix default message for server ping and pong frames. (#3308)

• Fix tests/test_connector.py typo and tests/autobahn/server.py duplicate loop def. (#3337)

• Fix false-negative indicator end_of_HTTP_chunk in StreamReader.readchunk function (#3361)

• Release HTTP response before raising status exception (#3364)

• Fix task cancellation when sendfile() syscall is used by static file handling. (#3383)

• Fix stack trace for asyncio.TimeoutError which was not logged, when it is caught in the handler. (#3414)

Improved Documentation

• Improve documentation of Application.make_handler parameters. (#3152)

• Fix BaseRequest.raw_headers doc. (#3215)

• Fix typo in TypeError exception reason in web.Application._handle (#3229)

• Make server access log format placeholder %b documentation reflect behavior and docstring. (#3307)

Deprecations and Removals

• Deprecate modification of session.requote_redirect_url (#2278)

• Deprecate stream.unread_data() (#3260)

• Deprecated use of boolean in resp.enable_compression() (#3318)

• Encourage creation of aiohttp public objects inside a coroutine (#3331)

• Drop dead Connection.detach() and Connection.writer. Both methods were broken for more than 2 years. (#3358)

• Deprecate app.loop, request.loop, client.loop and connector.loop properties. (#3374)

• Deprecate explicit debug argument. Use asyncio debug mode instead. (#3381)

• Deprecate body parameter in HTTPException (and derived classes) constructor. (#3385)

• Deprecate bare connector close, use async with connector: and await connector.close() instead. (#3417)

• Deprecate obsolete read_timeout and conn_timeout in ClientSession constructor. (#3438)

Misc

• #3341, #3351