decorate a bunch of items in a package and expose them as a public api

__init__.py

def _build_facade():
    import sys
    from .meta.api import scan
    this = sys.modules[__name__]
    registry = {}
    scan(this, registry=registry)
    globals().update(registry)
_build_facade()
del _build_facade

api.py

import venusian

def scan(pkg, registry=None):
    if registry is None:
        registry = {}
    scanner = venusian.Scanner(registry=registry)
    scanner.scan(pkg)
    return registry

def expose(wrapped):
    def callback(scanner, name, obj):
        scanner.registry[name] = wrapped
    venusian.attach(wrapped, callback)
    return wrapped

user.py

from .api import expose

@expose
class User(Base):
    name = Column(Text, nullable=False)