historic = true

可以实现一个callback 函数

def callback(result):

    print("llll", result)

pm = pluggy.PluginManager("myproject")

pm.add_hookspecs(MySpec)

# register plugins

pm.hook.myhook.call_historic(kwargs={"arg1": 10, "arg2": 30}, result_callback=callback)

pm.register(Plugin_1())

设置historic为true时，需要调用call_historic，通过dict传入hook参数，

如果需要处理hook返回值，需要传入result_callback, 回调函数

function = func

通过直接传入func，来设置func attributes，如果为None，则返回一个包装器setattr_hookspec_opts

通过@hookspec方式包装一个func，设置attributes，

set attributes 之后的func 可以在py模块和class类中识别到，

通过PluginManager.add_hookspecs 传入py或者class

hookspec = pluggy.HookspecMarker("myproject")

class MySpec:

    """A hook specification namespace."""

    @hookspec()

    def myhook(self, arg1, arg2):

        """My special little hook that you can customize."""

    def myhook1(self, arg1, arg2):

        """My special little hook that you can customize."""

    myhook1 = hookspec(function=myhook1)


pm = pluggy.PluginManager("myproject")

pm.add_hookspecs(MySpec)

pm.hook.myhook(arg1=1, arg2=2)

pm.hook.myhook1(arg1=1, arg2=2) 

firstresult = True

注册hook是1:N方式注册的，即一个hookspec 钩子规范，N个钩子函数实现，

如果firstresult=True，则在第一个不返回None的钩子调用时，结束改hook的调用，

即第 I 个hook是不返回None的，则在第 I 之后停止，调用hook数量是I <= N

class MySpec:

    """A hook specification namespace."""

    @hookspec(firstresult=True)

    def myhook(self, arg1, arg2):

        """My special little hook that you can customize."""

    # myhook = hookspec(historic=True)(myhook)

class Plugin_1:

    """A hook implementation namespace."""

    @hookimpl

    def myhook(self, arg1, arg2):

        print("inside Plugin_1.myhook()")


class Plugin_2:

    """A 2nd hook implementation namespace."""

    @hookimpl

    def myhook(self, arg1, arg2):

        print("inside Plugin_2.myhook()")

        return arg1 - arg2


class Plugin_3:

    """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_3())

pm.register(Plugin_2())

pm.register(Plugin_1())

results = pm.hook.myhook(arg1=1, arg2=2)

print(results) # -1,  Plugin_3的hook不会调用