code: def iter_setup_packages(srcdir, packages):
      
  
      for packagename in packages:
          package_parts = packagename.split('.')
          package_path = os.path.join(srcdir, *package_parts)
          setup_package = os.path.relpath(
              os.path.join(package_path, 'setup_package.py'))
  
          if os.path.isfile(setup_package):
              module = import_file(setup_package,
                                   name=packagename + '.setup_package')
              yield module
docs: A generator that finds and imports all of the ``setup_package.py``
      modules in the source packages.
  
      Returns
      -------
      modgen : generator
          A generator that yields (modname, mod), where `mod` is the module and
          `modname` is the module name for the ``setup_package.py`` modules.