How to get addon __name__ in another module into the same package or another subpackage?

Question

I built some functions into python module functions.py, but in it if I try to get the __name__ I get something like __name __.functions

How do you get the name of the addon a pythonic way?

I add some details:

Example module functions.py

def open_user_pref(context, addon_name):

    preferences = context.preferences.addons[addon_name].preferences
    bpy.ops.screen.userpref_show('INVOKE_DEFAULT')
    bpy.context.preferences.active_section = 'ADDONS'
    bpy.ops.preferences.addon_expand(module=addon_name)
    bpy.ops.preferences.addon_show(module=addon_name)

Example call from __init__.py

from . import functions

functions.open_user_pref(bpy.context, __name__)

But if I want to avoid the input name, I should find the exact name of the addon. So how can this be done?

def open_user_pref(contex):
    #addon_name = __name__.split(".")[0] ? This seems dangerous to me if this package becomes a subpackage

    preferences = context.preferences.addons[addon_name].preferences
    bpy.ops.screen.userpref_show('INVOKE_DEFAULT')
    bpy.context.preferences.active_section = 'ADDONS'
    bpy.ops.preferences.addon_expand(module=addon_name)
    bpy.ops.preferences.addon_show(module=addon_name)

Answer 1

The inspect module.

This is somewhat a generic python question, tho As it happens I have an addon that automates a lot of settings to create and register addons based on a folder structure. Wanted to keep it as simple as possible, and used the following to automate getting the importing module (addon) name.

Pretty sure this can be used to suit your needs.

In root folder of "bat_tools" addon

bat_tools/__init__.py

from .types.app import BATApp

bl_info = {
    "name": "BAT Tools",
    "author": "batFINGER",
    "location": "Every Bloody Where",
    "description": "A Collection of BAT Tools",
    # "warning": "Still in Testing",
    "version": (0, 0, 1), "blender": (2, 80, 0),
    "support": "TESTING",
    "category": "Toolkit",
}

app = BATApp()

register, unregister =  app.register()

and a snippet from the class def in the submodule. When the object is instanced set the name and package from the module which imported it. (Code from stackoverflow.com search Get __name__ of calling function's module in Python)

bat_tools/types/app.py .

class BATApp:
    @property
    def prefs(self):
        from bpy import context
        pref = context.preferences.addons.get(self.name)
        if pref:
            return getattr(pref.preferences, self.name, None)
        return None


    def __init__(self, **kwargs):
        # get the details of calling module

        import inspect
        frm = inspect.stack()[1]
        mod = inspect.getmodule(frm[0])
        # print(mod.__name__, mod.__package__, mod.__file__)
        self.name = mod.__name__
        self.package = mod.__package__
        path = Path(mod.__file__)

BTW see no issue with splitting the package as commented, (and illustrated in question) foo.bar.foo since an addon is a base module, follows a naming convention which cannot be named "foo.bar" for example.