Example of Injector assisted injection using @provides.

gistfile1.py

from injector import *


class Session(object):
    def __init__(self, key, site):
        self.key = key
        self.site = site


SessionKey = Key('SessionKey')


class Site(object):
    def __init__(self, url):
        self.url = url

    def __repr__(self):
        return 'Site(%r)' % self.url


class SomeModule(Module):
    def configure(self, binder):
        binder.bind(SessionKey, to='foo')

    @provides(Session)
    @inject(key=SessionKey)
    def provides_session(self, key, site):
        return Session(key, site)


injector = Injector([SomeModule])


session_builder = injector.get(AssistedBuilder(Session))
foo = Site('foo.com')
session = session_builder.build(site=foo)
assert session.site is foo
print session.key, session.site