In the past, distutils could use either the zipfile/tarfile modules or the external programs tar, zip and friends.  This is told in the documentation and checked in the tests.

I suspect that the docs and tests are now outdated.  For example, some tests will be skipped if the tar program is not found, even if the code would have used the tarfile module and run successfully.  I’ll look into this for packaging, but I don’t have the time right now to go over the distutils test and docs for 2.7 and 3.2.