Technically, you can do this with Python, but you'll have to use some dark magic to get the importing module namespace, in order to manipulate it. It'll not be pretty.

Instead, in normal Python it is the importing module that must decide who has access to its own namespace, and who must live within a separated one. It has a completely different set of costs and benefits. (I sometimes wonder if Guido used Perl as a counterexample when creating Python - its principles are almost completely opposite.)