lazy.py

class LazyLazy(dict):
    def __init__(self):
        self.factories = {}
        self.cache = {}

    def register(self, key, factory):
        self.factories[key] = factory

    def factory(self, key):
        def decorator(factory):
            self.factories[key] = factory
            return factory
        return decorator

    def __dir__(self):
        return dir(self.factories)

    def __getitem__(self, key):
        existing = self.cache.get(key)
        if existing:
            return existing

        fac = self.factories.get(key)
        if fac is None:
            raise AttributeError(f"Module has no attribute {key!r}")

        ret = fac()
        self.cache[key] = ret
        return ret

    def __contains__(self, key):
        return key in self.factories

main.py

import one
import two

print(one.stub_types())
print(two.stub_types())

# Prints
# {'x': <class 'one.Homonymous'>}
# {'x': <class 'two.Homonymous'>}

one.py

import typing
import lazy

if typing.TYPE_CHECKING:

    class Homonymous:
        pass

THIS_MODULE = lazy.LazyLazy()


@THIS_MODULE.factory("Homonymous")
def _build_Homonymous():
    class Homonymous:
        def __repr__(self):
            return "one.Homonymous"

    return Homonymous


@THIS_MODULE.factory("stub")
def _build_stub():
    def stub(x: "Homonymous"):
        pass

    return stub


@THIS_MODULE.factory("other_member")
def _build_other_member():
    raise RuntimeError('Was not expecting to access other_member! You should not see this.')


@THIS_MODULE.factory("stub_types")
def _build_stub_types():
    def stub_types():
        stub = THIS_MODULE['stub']
        return typing.get_type_hints(stub, globalns=THIS_MODULE, localns=THIS_MODULE)

    return stub_types


def __getattr__(key):
    return THIS_MODULE[key]

two.py

import typing
import lazy

if typing.TYPE_CHECKING:

    class Homonymous:
        pass


THIS_MODULE = lazy.LazyLazy()


@THIS_MODULE.factory("Homonymous")
def _build_Homonymous():
    class Homonymous:
        def __repr__(self):
            return "two.Homonymous"

    return Homonymous


@THIS_MODULE.factory("stub")
def _build_stub():
    def stub(x: "Homonymous"):
        pass

    return stub


@THIS_MODULE.factory("stub_types")
def _build_stub_types():
    def stub_types():
        stub = THIS_MODULE['stub']
        return typing.get_type_hints(stub, globalns=THIS_MODULE, localns=THIS_MODULE)

    return stub_types


def __getattr__(key):
    return THIS_MODULE[key]