code: def filter_installed_packages(packages):
      
      yb = yum.YumBase()
      package_list = yb.doPackageLists()
      temp_cache = {p.base_package_name: 1 for p in package_list['installed']}
  
      _pkgs = [p for p in packages if not temp_cache.get(p, False)]
      return _pkgs
docs: Return a list of packages that require installation.