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Metadata-Version: 2.1 | |
Name: h11 | |
Version: 0.14.0 | |
Summary: A pure-Python, bring-your-own-I/O implementation of HTTP/1.1 | |
Home-page: https://github.com/python-hyper/h11 | |
Author: Nathaniel J. Smith | |
Author-email: njs@pobox.com | |
License: MIT | |
Classifier: Development Status :: 3 - Alpha | |
Classifier: Intended Audience :: Developers | |
Classifier: License :: OSI Approved :: MIT License | |
Classifier: Programming Language :: Python :: Implementation :: CPython | |
Classifier: Programming Language :: Python :: Implementation :: PyPy | |
Classifier: Programming Language :: Python :: 3 | |
Classifier: Programming Language :: Python :: 3 :: Only | |
Classifier: Programming Language :: Python :: 3.7 | |
Classifier: Programming Language :: Python :: 3.8 | |
Classifier: Programming Language :: Python :: 3.9 | |
Classifier: Programming Language :: Python :: 3.10 | |
Classifier: Topic :: Internet :: WWW/HTTP | |
Classifier: Topic :: System :: Networking | |
Requires-Python: >=3.7 | |
License-File: LICENSE.txt | |
Requires-Dist: typing-extensions ; python_version < "3.8" | |
h11 | |
=== | |
.. image:: https://travis-ci.org/python-hyper/h11.svg?branch=master | |
:target: https://travis-ci.org/python-hyper/h11 | |
:alt: Automated test status | |
.. image:: https://codecov.io/gh/python-hyper/h11/branch/master/graph/badge.svg | |
:target: https://codecov.io/gh/python-hyper/h11 | |
:alt: Test coverage | |
.. image:: https://readthedocs.org/projects/h11/badge/?version=latest | |
:target: http://h11.readthedocs.io/en/latest/?badge=latest | |
:alt: Documentation Status | |
This is a little HTTP/1.1 library written from scratch in Python, | |
heavily inspired by `hyper-h2 <https://hyper-h2.readthedocs.io/>`_. | |
It's a "bring-your-own-I/O" library; h11 contains no IO code | |
whatsoever. This means you can hook h11 up to your favorite network | |
API, and that could be anything you want: synchronous, threaded, | |
asynchronous, or your own implementation of `RFC 6214 | |
<https://tools.ietf.org/html/rfc6214>`_ -- h11 won't judge you. | |
(Compare this to the current state of the art, where every time a `new | |
network API <https://trio.readthedocs.io/>`_ comes along then someone | |
gets to start over reimplementing the entire HTTP protocol from | |
scratch.) Cory Benfield made an `excellent blog post describing the | |
benefits of this approach | |
<https://lukasa.co.uk/2015/10/The_New_Hyper/>`_, or if you like video | |
then here's his `PyCon 2016 talk on the same theme | |
<https://www.youtube.com/watch?v=7cC3_jGwl_U>`_. | |
This also means that h11 is not immediately useful out of the box: | |
it's a toolkit for building programs that speak HTTP, not something | |
that could directly replace ``requests`` or ``twisted.web`` or | |
whatever. But h11 makes it much easier to implement something like | |
``requests`` or ``twisted.web``. | |
At a high level, working with h11 goes like this: | |
1) First, create an ``h11.Connection`` object to track the state of a | |
single HTTP/1.1 connection. | |
2) When you read data off the network, pass it to | |
``conn.receive_data(...)``; you'll get back a list of objects | |
representing high-level HTTP "events". | |
3) When you want to send a high-level HTTP event, create the | |
corresponding "event" object and pass it to ``conn.send(...)``; | |
this will give you back some bytes that you can then push out | |
through the network. | |
For example, a client might instantiate and then send a | |
``h11.Request`` object, then zero or more ``h11.Data`` objects for the | |
request body (e.g., if this is a POST), and then a | |
``h11.EndOfMessage`` to indicate the end of the message. Then the | |
server would then send back a ``h11.Response``, some ``h11.Data``, and | |
its own ``h11.EndOfMessage``. If either side violates the protocol, | |
you'll get a ``h11.ProtocolError`` exception. | |
h11 is suitable for implementing both servers and clients, and has a | |
pleasantly symmetric API: the events you send as a client are exactly | |
the ones that you receive as a server and vice-versa. | |
`Here's an example of a tiny HTTP client | |
<https://github.com/python-hyper/h11/blob/master/examples/basic-client.py>`_ | |
It also has `a fine manual <https://h11.readthedocs.io/>`_. | |
FAQ | |
--- | |
*Whyyyyy?* | |
I wanted to play with HTTP in `Curio | |
<https://curio.readthedocs.io/en/latest/tutorial.html>`__ and `Trio | |
<https://trio.readthedocs.io>`__, which at the time didn't have any | |
HTTP libraries. So I thought, no big deal, Python has, like, a dozen | |
different implementations of HTTP, surely I can find one that's | |
reusable. I didn't find one, but I did find Cory's call-to-arms | |
blog-post. So I figured, well, fine, if I have to implement HTTP from | |
scratch, at least I can make sure no-one *else* has to ever again. | |
*Should I use it?* | |
Maybe. You should be aware that it's a very young project. But, it's | |
feature complete and has an exhaustive test-suite and complete docs, | |
so the next step is for people to try using it and see how it goes | |
:-). If you do then please let us know -- if nothing else we'll want | |
to talk to you before making any incompatible changes! | |
*What are the features/limitations?* | |
Roughly speaking, it's trying to be a robust, complete, and non-hacky | |
implementation of the first "chapter" of the HTTP/1.1 spec: `RFC 7230: | |
HTTP/1.1 Message Syntax and Routing | |
<https://tools.ietf.org/html/rfc7230>`_. That is, it mostly focuses on | |
implementing HTTP at the level of taking bytes on and off the wire, | |
and the headers related to that, and tries to be anal about spec | |
conformance. It doesn't know about higher-level concerns like URL | |
routing, conditional GETs, cross-origin cookie policies, or content | |
negotiation. But it does know how to take care of framing, | |
cross-version differences in keep-alive handling, and the "obsolete | |
line folding" rule, so you can focus your energies on the hard / | |
interesting parts for your application, and it tries to support the | |
full specification in the sense that any useful HTTP/1.1 conformant | |
application should be able to use h11. | |
It's pure Python, and has no dependencies outside of the standard | |
library. | |
It has a test suite with 100.0% coverage for both statements and | |
branches. | |
Currently it supports Python 3 (testing on 3.7-3.10) and PyPy 3. | |
The last Python 2-compatible version was h11 0.11.x. | |
(Originally it had a Cython wrapper for `http-parser | |
<https://github.com/nodejs/http-parser>`_ and a beautiful nested state | |
machine implemented with ``yield from`` to postprocess the output. But | |
I had to take these out -- the new *parser* needs fewer lines-of-code | |
than the old *parser wrapper*, is written in pure Python, uses no | |
exotic language syntax, and has more features. It's sad, really; that | |
old state machine was really slick. I just need a few sentences here | |
to mourn that.) | |
I don't know how fast it is. I haven't benchmarked or profiled it yet, | |
so it's probably got a few pointless hot spots, and I've been trying | |
to err on the side of simplicity and robustness instead of | |
micro-optimization. But at the architectural level I tried hard to | |
avoid fundamentally bad decisions, e.g., I believe that all the | |
parsing algorithms remain linear-time even in the face of pathological | |
input like slowloris, and there are no byte-by-byte loops. (I also | |
believe that it maintains bounded memory usage in the face of | |
arbitrary/pathological input.) | |
The whole library is ~800 lines-of-code. You can read and understand | |
the whole thing in less than an hour. Most of the energy invested in | |
this so far has been spent on trying to keep things simple by | |
minimizing special-cases and ad hoc state manipulation; even though it | |
is now quite small and simple, I'm still annoyed that I haven't | |
figured out how to make it even smaller and simpler. (Unfortunately, | |
HTTP does not lend itself to simplicity.) | |
The API is ~feature complete and I don't expect the general outlines | |
to change much, but you can't judge an API's ergonomics until you | |
actually document and use it, so I'd expect some changes in the | |
details. | |
*How do I try it?* | |
.. code-block:: sh | |
$ pip install h11 | |
$ git clone git@github.com:python-hyper/h11 | |
$ cd h11/examples | |
$ python basic-client.py | |
and go from there. | |
*License?* | |
MIT | |
*Code of conduct?* | |
Contributors are requested to follow our `code of conduct | |
<https://github.com/python-hyper/h11/blob/master/CODE_OF_CONDUCT.md>`_ in | |
all project spaces. | |