History¶

v4.1.0¶

27 Aug 2023

Re-synced implementation with CPython 3.8, removing the compatibility code introduced for compatibility with older Pythons.
Require Python 3.8 or later.

02 Jan 2023

Require Python 3.7 or later.

Incorporate Tidelift sponsorship.

13 Aug 2021

#4: Add singledispatchmethod from Python 3.8.

Incorporate minor changes from Python 3.8.

26 May 2021

#3 and bpo-23572: Fix behavior when metaclass implements bool.

25 Feb 2021

Fixed DeprecationWarnings referring to members from collections.abc referenced from collections.

20 Feb 2021

#1: Added support for annotations as found on Python 3.7.

20 Feb 2021

Adopt semver for versioning.

Adopt jaraco/skeleton for packaging.

Declare support through 3.9.

#2: Tests now pass under pytest and when typing is present.

Hosting moved to Github.

Now maintained by jaraco. Thanks to Łukasz Langa for the original backport and maintenance.

Last version before switch to semver for versioning.

Should now install flawlessly on PyPy as well. Thanks to Ryan Petrello for finding and fixing the setup.py issue.

Updated to the reference implementation as of 02-July-2013.

more predictable dispatch order when abstract base classes are in use: abstract base classes are now inserted into the MRO of the argument’s class where their functionality is introduced, i.e. issubclass(cls, abc) returns True for the class itself but returns False for all its direct base classes. Implicit ABCs for a given class (either registered or inferred from the presence of a special method like __len__) are inserted directly after the last ABC explicitly listed in the MRO of said class. This also means there are less “ambiguous dispatch” exceptions raised.
better test coverage and improved docstrings

Updated to the reference implementation as of 31-May-2013.

better performance
fixed a corner case with PEP 435 enums
calls to dispatch() also cached
dispatching algorithm now now a module-level routine called _find_impl() with a simplified implementation and proper documentation
dispatch() now handles all caching-related activities
terminology more consistent: “overload” -> “implementation”