Metadata-Version: 1.2
Name: aiocontextvars
Version: 0.2.2
Summary: Asyncio support for PEP-567 contextvars backport.
Home-page: https://github.com/fantix/aiocontextvars
Author: Fantix King
Author-email: fantix.king@gmail.com
License: BSD license
Description: ==============
        aiocontextvars
        ==============
        
        .. image:: https://img.shields.io/pypi/v/aiocontextvars.svg
                :target: https://pypi.python.org/pypi/aiocontextvars
        
        .. image:: https://img.shields.io/travis/fantix/aiocontextvars.svg
                :target: https://travis-ci.org/fantix/aiocontextvars
        
        **IMPORTANT:** This package will be deprecated after
        `contextvars asyncio backport`_ is fixed. Before then, this library
        experimentally provides the missing asyncio support for the
        ``contextvars`` backport library. Please read more in Python 3.7 `contextvars
        documentation <https://docs.python.org/3/library/contextvars.html>`_.
        
        
        Compatibility
        -------------
        
        In Python 3.7 this package *is* 100% ``contextvars``.
        
        In Python 3.5 and 3.6, this package added asyncio support to the PEP-567
        backport package also named ``contextvars``, in a very different way than
        Python 3.7 ``contextvars`` implementation:
        
        1. ``call_soon()`` and family methods.
        
        Python 3.7 added keyword argument ``context`` to ``call_soon()`` and its family
        methods. By default those methods will copy (inherit) the current context and
        run the given method in that context. But ``aiocontextvars`` won't touch the
        loop, so in order to achieve the same effect, you'll need to::
        
            loop.call_soon(copy_context().run, my_meth)
        
        2. Task local.
        
        Python 3.7 used above keyword argument ``context`` in ``Task`` to make sure
        that each step of a coroutine is ran in the same context inherited at the time
        its driving task was created. Meanwhile, ``aiocontextvars`` uses
        ``Task.current_task()`` to achieve similar effect: it hacks asyncio and
        attaches a copied context to the task on its creation, and replaces thread
        local with current task instance to share the context. This behaves identically
        to Python 3.7 in most times. What you need to do is to import
        ``aiocontextvars`` before creating loops.
        
        3. Custom tasks and loops.
        
        Because above hack is done by replacing ``asyncio.get_event_loop`` and
        ``loop.create_task``, therefore tasks and loops created by custom/private API
        won't behave correctly as expected, e.g. ``uvloop.new_event_loop()`` or
        ``asyncio.Task()``. Also, event loops created before importing
        ``aiocontextvars`` are not patched either. So over all, you should import
        ``aiocontextvars`` at the beginning before creating event loops, and always use
        ``asyncio.*`` to operate loops/policies, and public asyncio API to create
        tasks.
        
        
        Credits
        -------
        
        Fantix King is the author and maintainer of this library. This library is open
        source software under BSD license.
        
        .. _contextvars asyncio backport: https://github.com/MagicStack/contextvars/issues/2
        
        
        =======
        History
        =======
        
        0.2.1 (2018-10-24)
        ------------------
        
        * Changed to single module layout.
        * Updated README.
        
        0.2.0 (2018-09-09)
        ------------------
        
        **This is a breaking change.** Most implementation is replaced with
        ``contextvars``. In Python 3.5 and 3.6, ``aiocontextvars`` depends on
        ``contextvars`` the PEP-567 backport in PyPI, and patches it to partially
        support asyncio; in Python 3.7 ``aiocontextvars`` is only a delegate to the
        built-in ``contextvars`` library.
        
        * Modified ``ContextVar.set()`` to return a token.
        * Added ``ContextVar.reset(token)``.
        * Removed ``ContextVar.delete()``.
        * Removed ``enable_inherit()`` and ``disable_inherit()``, inherit is always enabled.
        * Added ``copy_context()`` and ``Context.run()``.
        * Removed ``Context.current()`` and ``Context.inherited``.
        * Fixed issue that ``set_event_loop(None)`` fails (contributed by J.J. Jackson in #10 #11)
        
        0.1.2 (2018-04-04)
        ------------------
        
        * Supported Python 3.5.
        
        0.1.1 (2017-12-03)
        ------------------
        
        * Fixed setup.py
        
        0.1.0 (2017-12-03)
        ------------------
        
        * First release on PyPI.
        
Keywords: aiocontextvars
Platform: UNKNOWN
Classifier: Development Status :: 4 - Beta
Classifier: Intended Audience :: Developers
Classifier: License :: OSI Approved :: BSD License
Classifier: Natural Language :: English
Classifier: Programming Language :: Python :: 3
Classifier: Programming Language :: Python :: 3.5
Classifier: Programming Language :: Python :: 3.6
Requires-Python: >=3.5
