pluggy 0.8.0

plugin and hook calling mechanisms for python

pluggy - A minimalist production ready plugin system

This is the core framework used by the pytest, tox, and devpi projects.

Please read the docs to learn more!

A definitive example

import pluggy

hookspec = pluggy.HookspecMarker("myproject")
hookimpl = pluggy.HookimplMarker("myproject")


class MySpec(object):
    """A hook specification namespace.
    """

    @hookspec
    def myhook(self, arg1, arg2):
        """My special little hook that you can customize.
        """


class Plugin_1(object):
    """A hook implementation namespace.
    """

    @hookimpl
    def myhook(self, arg1, arg2):
        print("inside Plugin_1.myhook()")
        return arg1 + arg2


class Plugin_2(object):
    """A 2nd hook implementation namespace.
    """

    @hookimpl
    def myhook(self, arg1, arg2):
        print("inside Plugin_2.myhook()")
        return arg1 - arg2


# create a manager and add the spec
pm = pluggy.PluginManager("myproject")
pm.add_hookspecs(MySpec)

# register plugins
pm.register(Plugin_1())
pm.register(Plugin_2())

# call our ``myhook`` hook
results = pm.hook.myhook(arg1=1, arg2=2)
print(results)

pluggy 0.8.0 (2018-10-15)

Features

• #177: Add get_hookimpls() method to hook callers.

Trivial/Internal Changes

• #165: Add changelog in long package description and documentation.

• #172: Add a test exemplifying the opt-in nature of spec defined args.

• #57: Encapsulate hook specifications in a type for easier introspection.

Changelog

pluggy 0.7.1 (2018-07-28)

Deprecations and Removals

• #116: Deprecate the implprefix kwarg to PluginManager and instead expect users to start using explicit HookimplMarker everywhere.

Features

• #122: Add .plugin member to PluginValidationError to access failing plugin during post-mortem.

• #138: Add per implementation warnings support for hookspecs allowing for both deprecation and future warnings of legacy and (future) experimental hooks respectively.

Bug Fixes

• #110: Fix a bug where _HookCaller.call_historic() would call the proc arg even when the default is None resulting in a TypeError.

• #160: Fix problem when handling VersionConflict errors when loading setuptools plugins.

Improved Documentation

• #123: Document how exceptions are handled and how the hook call loop terminates immediately on the first error which is then delivered to any surrounding wrappers.

• #136: Docs rework including a much better introduction and comprehensive example set for new users. A big thanks goes out to @obestwalter for the great work!

Trivial/Internal Changes

• #117: Break up the main monolithic package modules into separate modules by concern

• #131: Automate setuptools wheels building and PyPi upload using TravisCI.

• #153: Reorganize tests more appropriately by modules relating to each internal component/feature. This is in an effort to avoid (future) duplication and better separation of concerns in the test set.

• #156: Add HookImpl.__repr__() for better debugging.

• #66: Start using towncrier and a custom tox environment to prepare releases!

pluggy 0.7.0 (Unreleased)

• #160: We discovered a deployment issue so this version was never released to PyPI, only the tag exists.

pluggy 0.6.0 (2017-11-24)

• Add CI testing for the features, release, and master branches of pytest (PR #79).

• Document public API for _Result objects passed to wrappers (PR #85).

• Document and test hook LIFO ordering (PR #85).

• Turn warnings into errors in test suite (PR #89).

• Deprecate _Result.result (PR #88).

• Convert _Multicall to a simple function distinguishing it from the legacy version (PR #90).

• Resolve E741 errors (PR #96).

• Test and bug fix for unmarked hook collection (PRs #97 and #102).

• Drop support for EOL Python 2.6 and 3.3 (PR #103).

• Fix inspect based arg introspection on py3.6 (PR #94).

pluggy 0.5.2 (2017-09-06)

• fix bug where firstresult wrappers were being sent an incorrectly configured _Result (a list was set instead of a single value). Add tests to check for this as well as _Result.force_result() behaviour. Thanks to @tgoodlet for the PR #72.

• fix incorrect getattr of DeprecationWarning from the warnings module. Thanks to @nicoddemus for the PR #77.

• hide pytest tracebacks in certain core routines. Thanks to @nicoddemus for the PR #80.

pluggy 0.5.1 (2017-08-29)

• fix a bug and add tests for case where firstresult hooks return None results. Thanks to @RonnyPfannschmidt and @tgoodlet for the issue (#68) and PR (#69) respectively.

pluggy 0.5.0 (2017-08-28)

• fix bug where callbacks for historic hooks would not be called for already registered plugins. Thanks @vodik for the PR and @hpk42 for further fixes.

• fix #17 by considering only actual functions for hooks this removes the ability to register arbitrary callable objects which at first glance is a reasonable simplification, thanks @RonnyPfannschmidt for report and pr.

• fix #19: allow registering hookspecs from instances. The PR from @tgoodlet also modernized the varnames implementation.

• resolve #32: split up the test set into multiple modules. Thanks to @RonnyPfannschmidt for the PR and @tgoodlet for the initial request.

• resolve #14: add full sphinx docs. Thanks to @tgoodlet for PR #39.

• add hook call mismatch warnings. Thanks to @tgoodlet for the PR #42.

• resolve #44: move to new-style classes. Thanks to @MichalTHEDUDE for PR #46.

• add baseline benchmarking/speed tests using pytest-benchmark in PR #54. Thanks to @tgoodlet.

• update the README to showcase the API. Thanks to @tgoodlet for the issue and PR #55.

• deprecate __multicall__ and add a faster call loop implementation. Thanks to @tgoodlet for PR #58.

• raise a comprehensible error when a hookimpl is called with positional args. Thanks to @RonnyPfannschmidt for the issue and @tgoodlet for PR #60.

• fix the firstresult test making it more complete and remove a duplicate of that test. Thanks to @tgoodlet for PR #62.

pluggy 0.4.0 (2016-09-25)

• add has_plugin(name) method to pluginmanager. thanks @nicoddemus.

• fix #11: make plugin parsing more resilient against exceptions from __getattr__ functions. Thanks @nicoddemus.

• fix issue #4: specific HookCallError exception for when a hook call provides not enough arguments.

• better error message when loading setuptools entrypoints fails due to a VersionConflict. Thanks @blueyed.

pluggy 0.3.1 (2015-09-17)

• avoid using deprecated-in-python3.5 getargspec method. Thanks @mdboom.

pluggy 0.3.0 (2015-05-07)

initial release