The other thread had some claims (*) that made me wonder - why are the tests in Python kept in Lib/ at all? AFAIK, this is rather an unusual project structure. Tests usually have a top-level directory of their own, in parallel to Lib/, Doc/ and others. Some effects of this in other projects: * The tests usually aren't even installed. The user can run them during installation, but once it goes through, tests are not copied into /usr/whatever... * Tests naturally become "developer-domain", removed from the "user-domain". No sane user would even consider using code from inside the Tests/ directory and somehow expect it to keep working in later versions. In addition, tests are then usually documented in special "hacking guides" and "developer docs" instead of in the official documentation of the project. This mail can appear as if advocating the transfer of Lib/test into Tests/, but this is not my intention here. Honest :-) I'm just trying to understand the history and rationale behind this structure in the CPython project. Eli (*) I refer to this reasoning someone raised: "test.support is part of the tests" + "tests are part of stdlib" --> "test.support must be documented where the rest of stdlib is"