py-context 0.3.1
Python dict with stacked context data
License: MIT
Keywords: context stack

==========
Py-Context
==========

.. image:: https://badge.fury.io/py/py-context.png
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.. image:: https://travis-ci.org/dealertrack/py-context.png?branch=master
    :target: https://travis-ci.org/dealertrack/py-context

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Python dict with stacked context data

* Free software: MIT license
* GitHub: https://github.com/dealertrack/py-context

Installing
----------

You can install ``py-context`` using pip::

    $ pip install py-context

Example
-------

::

    >>> context = Context({'user': 'Fred', 'city': 'Bedrock'})
    >>> context['user']
    'Fred'
    >>> context['city']
    'Bedrock'
    >>> context.push({'user': 'Barney'})
    >>> context['user']
    'Barney'
    >>> context['city']
    'Bedrock'
    >>> context.pop()
    {'user': 'Barney'}
    >>> context['user']
    'Fred'

Context also supports signals.
Signal handler can be attached globally::

    >>> @context_key_changed.connect
    ... def handler(sender, context, key, new, old):
    ...     print(key, new, old)

    >>> context = Context()
    >>> context['hello'] = 'world'
    hello world <Missing>

Or to individual context instances::

    >>> def handler(sender, context, key, new, old):
    ...     print(key, new, old)
    >>> context = Context()
    >>> context_key_changed.connect(handler, sender=context)

Supported signals::

    >>> @context_initialized.connect
    ... def handler(sender, context):
    ...     pass

    >>> @pre_context_changed.connect
    ... def handler(sender, context):
    ...     pass

    >>> @post_context_changed.connect
    ... def handler(sender, context):
    ...     pass

    >>> @context_key_changed.connect
    ... def handler(sender, context, key, new, old):
    ...     pass

Additionally, ``ClassSignallingContext`` can be used to subscribe signals
by sender classes, not instances::

    >>> class TestContext(ClassSignallingContext):
    ...     pass
    >>> def context_key_changed_handler(sender, context, key, new, old):
    ...     print(key, new, old)
    >>> _ = context_key_changed.connect(context_key_changed_handler, sender=TestContext)

    >>> context = Context()
    >>> class_context = TestContext()

    >>> context['foo'] = 'bar'
    >>> class_context['foo'] = 'bar'
    foo bar <Missing>

Testing
-------

To run the tests you need to install testing requirements first::

    $ make install

Then to run tests, you can use ``nosetests`` or simply use Makefile command::

    $ nosetests -sv
    # or
    $ make test




History
-------

0.3.1 (2018-04-11)
~~~~~~~~~~~~~~~~~~

* Added support for ``*args``, ``**kwargs`` in ``Context.push()``.
* Added ``__dir__`` support.

0.3.0 (2018-02-16)
~~~~~~~~~~~~~~~~~~

* Added signals support - ``context_initialized``, ``pre_context_changed``,
  ``post_context_changed`` and ``context_key_changed``. See README for examples.

0.2.1 (2017-07-28)
~~~~~~~~~~~~~~~~~~

* Excluding tests from being installed

0.2.0 (2017-05-11)
~~~~~~~~~~~~~~~~~~

* Add attribute support
* Add make watch target

0.1.0 (2017-03-22)
~~~~~~~~~~~~~~~~~~

* First release on PyPI.


Credits
-------

Originally ``Context`` was taken from `Genshi <https://genshi.edgewall.org/>`_ project.
See ``LICENSE`` for copyright notices.

Development Lead
~~~~~~~~~~~~~~~~

* Miroslav Shubernetskiy  - https://github.com/miki725

Contributors
~~~~~~~~~~~~

* Serkan Hosca - https://github.com/shosca


Copyright (C) 2006-2010 Edgewall Software

Copyright (C) 2017 Dealertrack Technologies, Inc.

All rights reserved.

::

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions
    are met:

    1. Redistributions of source code must retain the above copyright
       notice, this list of conditions and the following disclaimer.
    2. Redistributions in binary form must reproduce the above copyright
       notice, this list of conditions and the following disclaimer in
       the documentation and/or other materials provided with the
       distribution.
    3. The name of the author may not be used to endorse or promote
       products derived from this software without specific prior
       written permission.

    THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
    OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
    WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
    ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
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    GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
    INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
    IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
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