`zope.interface`

.. image:: https://img.shields.io/pypi/v/zope.interface.svg :target: https://pypi.python.org/pypi/zope.interface/ :alt: Latest Version

.. image:: https://travis-ci.org/zopefoundation/zope.interface.png?branch=master :target: https://travis-ci.org/zopefoundation/zope.interface

.. image:: https://readthedocs.org/projects/zopeinterface/badge/?version=latest :target: https://zopeinterface.readthedocs.io/en/latest/ :alt: Documentation Status

This package is intended to be independently reusable in any Python project. It is maintained by the Zope Toolkit project <http://docs.zope.org/zopetoolkit/>_.

This package provides an implementation of "object interfaces" for Python. Interfaces are a mechanism for labeling objects as conforming to a given API or contract. So, this package can be considered as implementation of the Design By Contract_ methodology support in Python.

.. Design By Contract: http://en.wikipedia.org/wiki/Designby_contract

For detailed documentation, please see https://zopeinterface.readthedocs.io/en/latest/

Changes

4.3.3 (2016-12-13)

Correct typos and ReST formatting errors in documentation.
Add API documentation for the adapter registry.
Ensure that the LICENSE.txt file is included in built wheels.
Fix C optimizations broken on Py3k. See the Python bug at: http://bugs.python.org/issue15657 (https://github.com/zopefoundation/zope.interface/issues/60)

4.3.2 (2016-09-05)

Fix equality testing of implementedBy objects and proxies. (https://github.com/zopefoundation/zope.interface/issues/55)

4.3.1 (2016-08-31)

Support Components subclasses that are not hashable. (https://github.com/zopefoundation/zope.interface/issues/53)

4.3.0 (2016-08-31)

Add the ability to sort the objects returned by implementedBy. This is compatible with the way interface classes sort so they can be used together in ordered containers like BTrees. (https://github.com/zopefoundation/zope.interface/issues/42)
Make setuptools a hard dependency of setup.py. (https://github.com/zopefoundation/zope.interface/issues/13)
Change a linear algorithm (O(n)) in Components.registerUtility and Components.unregisterUtility into a dictionary lookup (O(1)) for hashable components. This substantially improves the time taken to manipulate utilities in large registries at the cost of some additional memory usage. (https://github.com/zopefoundation/zope.interface/issues/46)

4.2.0 (2016-06-10)

Add support for Python 3.5
Drop support for Python 2.6 and 3.2.

4.1.3 (2015-10-05)

Fix installation without a C compiler on Python 3.5 (https://github.com/zopefoundation/zope.interface/issues/24).

4.1.2 (2014-12-27)

Add support for PyPy3.
Remove unittest assertions deprecated in Python3.x.
Add zope.interface.document.asReStructuredText, which formats the generated text for an interface using ReST double-backtick markers.

4.1.1 (2014-03-19)

Add support for Python 3.4.

4.1.0 (2014-02-05)

Update boostrap.py to version 2.2.
Add @named(name) declaration, that specifies the component name, so it does not have to be passed in during registration.

4.0.5 (2013-02-28)

Fix a bug where a decorated method caused false positive failures on verifyClass().

4.0.4 (2013-02-21)

Fix a bug that was revealed by porting zope.traversing. During a loop, the loop body modified a weakref dict causing a RuntimeError error.

4.0.3 (2012-12-31)

Fleshed out PyPI Trove classifiers.

4.0.2 (2012-11-21)

Add support for Python 3.3.
Restored ability to install the package in the absence of setuptools.
LP #1055223: Fix test which depended on dictionary order and failed randomly in Python 3.3.

4.0.1 (2012-05-22)

Drop explicit DeprecationWarnings for "class advice" APIS (these APIs are still deprecated under Python 2.x, and still raise an exception under Python 3.x, but no longer cause a warning to be emitted under Python 2.x).

4.0.0 (2012-05-16)

Automated build of Sphinx HTML docs and running doctest snippets via tox.
Deprecate the "class advice" APIs from zope.interface.declarations: implements, implementsOnly, and classProvides. In their place, prefer the equivalent class decorators: @implementer, @implementer_only, and @provider. Code which uses the deprecated APIs will not work as expected under Py3k.
Remove use of '2to3' and associated fixers when installing under Py3k. The code is now in a "compatible subset" which supports Python 2.6, 2.7, and 3.2, including PyPy 1.8 (the version compatible with the 2.7 language spec).
Drop explicit support for Python 2.4 / 2.5 / 3.1.
Add support for PyPy.
Add support for continuous integration using tox and jenkins.
Add 'setup.py dev' alias (runs setup.py develop plus installs nose and coverage).
Add 'setup.py docs' alias (installs Sphinx and dependencies).
Replace all unittest coverage previously accomplished via doctests with unittests. The doctests have been moved into a docs section, managed as a Sphinx collection.
LP #910987: Ensure that the semantics of the lookup method of zope.interface.adapter.LookupBase are the same in both the C and Python implementations.
LP #900906: Avoid exceptions due to tne new __qualname__ attribute added in Python 3.3 (see PEP 3155 for rationale). Thanks to Antoine Pitrou for the patch.

3.8.0 (2011-09-22)

New module zope.interface.registry. This is code moved from zope.component.registry which implements a basic nonperistent component registry as zope.interface.registry.Components. This class was moved from zope.component to make porting systems (such as Pyramid) that rely only on a basic component registry to Python 3 possible without needing to port the entirety of the zope.component package. Backwards compatibility import shims have been left behind in zope.component, so this change will not break any existing code.
New tests_require dependency: zope.event to test events sent by Components implementation. The zope.interface package does not have a hard dependency on zope.event, but if zope.event is importable, it will send component registration events when methods of an instance of zope.interface.registry.Components are called.
New interfaces added to support zope.interface.registry.Components addition: ComponentLookupError, Invalid, IObjectEvent, ObjectEvent, IComponentLookup, IRegistration, IUtilityRegistration, IAdapterRegistration, ISubscriptionAdapterRegistration, IHandlerRegistration, IRegistrationEvent, RegistrationEvent, IRegistered, Registered, IUnregistered, Unregistered, IComponentRegistry, and IComponents.
No longer Python 2.4 compatible (tested under 2.5, 2.6, 2.7, and 3.2).

3.7.0 (2011-08-13)

Move changes from 3.6.2 - 3.6.5 to a new 3.7.x release line.

3.6.7 (2011-08-20)

Fix sporadic failures on x86-64 platforms in tests of rich comparisons of interfaces.

3.6.6 (2011-08-13)

LP #570942: Now correctly compare interfaces from different modules but with the same names.

N.B.: This is a less intrusive / destabilizing fix than the one applied in 3.6.3: we only fix the underlying cmp-alike function, rather than adding the other "rich comparison" functions.
Revert to software as released with 3.6.1 for "stable" 3.6 release branch.

3.6.5 (2011-08-11)

LP #811792: work around buggy behavior in some subclasses of zope.interface.interface.InterfaceClass, which invoke __hash__ before initializing __module__ and __name__. The workaround returns a fixed constant hash in such cases, and issues a UserWarning.
LP #804832: Under PyPy, zope.interface should not build its C extension. Also, prevent attempting to build it under Jython.
Add a tox.ini for easier xplatform testing.
Fix testing deprecation warnings issued when tested under Py3K.

3.6.4 (2011-07-04)

LP 804951: InterfaceClass instances were unhashable under Python 3.x.

3.6.3 (2011-05-26)

LP #570942: Now correctly compare interfaces from different modules but with the same names.

3.6.2 (2011-05-17)

Moved detailed documentation out-of-line from PyPI page, linking instead to http://docs.zope.org/zope.interface .
Fixes for small issues when running tests under Python 3.2 using zope.testrunner.
LP # 675064: Specify return value type for C optimizations module init under Python 3: undeclared value caused warnings, and segfaults on some 64 bit architectures.
setup.py now raises RuntimeError if you don't have Distutils installed when running under Python 3.

3.6.1 (2010-05-03)

A non-ASCII character in the changelog made 3.6.0 uninstallable on Python 3 systems with another default encoding than UTF-8.
Fix compiler warnings under GCC 4.3.3.

3.6.0 (2010-04-29)

LP #185974: Clear the cache used by Specificaton.get inside Specification.changed. Thanks to Jacob Holm for the patch.
Add support for Python 3.1. Contributors:

Lennart Regebro Martin v Loewis Thomas Lotze Wolfgang Schnerring

The 3.1 support is completely backwards compatible. However, the implements syntax used under Python 2.X does not work under 3.X, since it depends on how metaclasses are implemented and this has changed. Instead it now supports a decorator syntax (also under Python 2.X)::

class Foo: implements(IFoo) ...

can now also be written::

@implementer(IFoo): class Foo: ...

There are 2to3 fixers available to do this change automatically in the zope.fixers package.
Python 2.3 is no longer supported.

3.5.4 (2009-12-23)

Use the standard Python doctest module instead of zope.testing.doctest, which has been deprecated.

3.5.3 (2009-12-08)

Fix an edge case: make providedBy() work when a class has 'provides' in its slots (see http://thread.gmane.org/gmane.comp.web.zope.devel/22490)

3.5.2 (2009-07-01)

BaseAdapterRegistry.unregister, unsubscribe: Remove empty portions of the data structures when something is removed. This avoids leaving references to global objects (interfaces) that may be slated for removal from the calling application.

3.5.1 (2009-03-18)

verifyObject: use getattr instead of hasattr to test for object attributes in order to let exceptions other than AttributeError raised by properties propagate to the caller
Add Sphinx-based documentation building to the package buildout configuration. Use the bin/docs command after buildout.
Improve package description a bit. Unify changelog entries formatting.
Change package's mailing list address to zope-dev at zope.org as zope3-dev at zope.org is now retired.

3.5.0 (2008-10-26)

Fix declaration of zopeinterface_coptimizations, it's not a top level package.
Add a DocTestSuite for odd.py module, so their tests are run.
Allow to bootstrap on Jython.
Fix https://bugs.launchpad.net/zope3/3.3/+bug/98388: ISpecification was missing a declaration for iro.
Add optional code optimizations support, which allows the building of C code optimizations to fail (Jython).
Replace _flatten with a non-recursive implementation, effectively making it 3x faster.

3.4.1 (2007-10-02)

Fix a setup bug that prevented installation from source on systems without setuptools.

3.4.0 (2007-07-19)

Final release for 3.4.0.

3.4.0b3 (2007-05-22)

When checking whether an object is already registered, use identity comparison, to allow adding registering with picky custom comparison methods.

3.3.0.1 (2007-01-03)

Made a reference to OverflowWarning, which disappeared in Python 2.5, conditional.

3.3.0 (2007/01/03)

New Features ++++++++++++

Refactor the adapter-lookup algorithim to make it much simpler and faster.

Also, implement more of the adapter-lookup logic in C, making debugging of application code easier, since there is less infrastructre code to step through.
Treat objects without interface declarations as if they declared that they provide zope.interface.Interface.
Add a number of richer new adapter-registration interfaces that provide greater control and introspection.
Add a new interface decorator to zope.interface that allows the setting of tagged values on an interface at definition time (see zope.interface.taggedValue).

Bug Fixes +++++++++

A bug in multi-adapter lookup sometimes caused incorrect adapters to be returned.

3.2.0.2 (2006-04-15)

Fix packaging bug: 'package_dir' must be a relative path.

3.2.0.1 (2006-04-14)

Packaging change: suppress inclusion of 'setup.cfg' in 'sdist' builds.

3.2.0 (2006-01-05)

Corresponds to the verison of the zope.interface package shipped as part of the Zope 3.2.0 release.

3.1.0 (2005-10-03)

Corresponds to the verison of the zope.interface package shipped as part of the Zope 3.1.0 release.
Made attribute resolution order consistent with component lookup order, i.e. new-style class MRO semantics.
Deprecate 'isImplementedBy' and 'isImplementedByInstancesOf' APIs in favor of 'implementedBy' and 'providedBy'.

3.0.1 (2005-07-27)

Corresponds to the verison of the zope.interface package shipped as part of the Zope X3.0.1 release.
Fix a bug reported by James Knight, which caused adapter registries to fail occasionally to reflect declaration changes.

3.0.0 (2004-11-07)

Corresponds to the verison of the zope.interface package shipped as part of the Zope X3.0.0 release.