I'm reading through the documentation some... Regarding this:
Note, by the way, that if you declare your dependencies in setup.py, you do not need to use the require() function in your scripts or modules, as long as you either install the project or use setup.py develop to do development work on it. (See "Development Mode" below for more details on using setup.py develop.)
I don't think this is quite true. In particular, I've noticed if you install a package A --multi-version, it fulfills the requirement for A. And if you have a package B that requires A, when you require('B') then A will be loaded (added to sys.path, more technically). But if B is *not* installed --multi-version you can start using it without require()ing it, and A won't have been loaded. Given this, I feel like I need to do the basic require()s in my __init__.py. But, at least for some packages (like SQLObject) I want the package to be usable without setuptools. It gets complicated then, because you'd have to do: try: import pkg_resources try: pkg_resources.require(...) except pkg_resources.ResolutionError: # Who knows how everything may be installed, lets be # optimistic and wait for a later ImportError... pass except ImportError: pass At least, that's the best I've figured out.