code: def find_packages_by_root_package(where):
      
      root_package = os.path.basename(where)
      packages = [ "%s.%s" % (root_package, sub_package)
                   for sub_package in find_packages(where)]
      packages.insert(0, root_package)
      return packages
docs: Better than excluding everything that is not needed,
      collect only what is needed.