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- Metadata-Version: 2.1
- Name: h11
- Version: 0.13.0
- 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
- Platform: UNKNOWN
- 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 :: 3.6
- Classifier: Programming Language :: Python :: 3.7
- Classifier: Programming Language :: Python :: 3.8
- Classifier: Programming Language :: Python :: 3.9
- Classifier: Topic :: Internet :: WWW/HTTP
- Classifier: Topic :: System :: Networking
- Requires-Python: >=3.6
- License-File: LICENSE.txt
- Requires-Dist: dataclasses ; python_version < "3.7"
- 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 3.6-3.9) 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.
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