A Minimal Pluggy Example

from framework import hook_implclass LowerHook:    @hook_impl    def start(pluggy_example):        pluggy_example.message = pluggy_example.message.lower()

pip install pluggy

import pluggy# These don't need to matchHOOK_NAMESPACE = "pluggy_example" PROJECT_NAME = "pluggy_example"hook_spec = pluggy.HookspecMarker(HOOK_NAMESPACE) hook_impl = pluggy.HookimplMarker(HOOK_NAMESPACE)class PluggyExampleSpecs:    """    This is where we spec out our frameworks hooks, I like to refer to them as    the lifecycle.  Each of these functions is a hook that we are exposing to    our users, with the kwargs that we expect to pass them.    """    @hook_spec    def start(self, pluggy_example: 'PluggyExample') -> None:        """        The first hook that runs.        """        pass    @hook_spec    def stop(self, pluggy_example: 'PluggyExample') -> None:        """        The last hook that runs.        """        passclass PluggyExample:    """    This may not need to be a class, but I wanted a container where all the    hooks had access to the message.  This made sense to me to do as a class.    """    def __init__(self, message="", hooks=None) -> None:        """        Setup the plugin manager and register all the hooks.        """        self._pm = pluggy.PluginManager(PROJECT_NAME)        self._pm.add_hookspecs(PluggyExampleSpecs)        self.message = message        self.hooks = hooks        if hooks:            self._register_hooks()    def _register_hooks(self) -> None:        for hook in self.hooks:            self._pm.register(hook)    def run(self):        """        Run the hooks in the documented order, and pass in any kwargs the hook        needs access to.  Here I am storing the message within this same class.        """        self._pm.hook.start(pluggy_example=self)        self._pm.hook.stop(pluggy_example=self)        return self.messageclass DefaultHook:    """    These are some hooks that run by default, maybe these are created by the    framework author.    """    @hook_impl    def start(pluggy_example):        pluggy_example.message = pluggy_example.message.upper()    @hook_impl    def stop(pluggy_example):        print(pluggy_example.message)if __name__ == "__main__":    """    The user of this framework can apply the hook in their own code without    changing the behavior of the framework, but the library has    implemented it's own default hooks.    """    pe = PluggyExample(        message="hello world",        hooks=[            DefaultHook,        ],    )    pe.run()

class LowerHook:    """    This is a new hook that a plugin author has created to modify the behavior    of the framework to lowercase the message.    """    @hook_impl    def start(pluggy_example):        pluggy_example.message = pluggy_example.message.lower()from pluggy_example import PluggyExample pe = PluggyExample(    message="hello world",    hooks=[        DefaultHook,        LowerHook    ],)pe.run()