code: def use_setuptools(
      version=DEFAULT_VERSION, download_base=DEFAULT_URL, to_dir=os.curdir,
      download_delay=15
  ):
      
      was_imported = 'pkg_resources' in sys.modules or 'setuptools' in sys.modules
      def do_download():
          egg = download_setuptools(version, download_base, to_dir, download_delay)
          sys.path.insert(0, egg)
          import setuptools; setuptools.bootstrap_install_from = egg
      try:
          import pkg_resources
      except ImportError:
          return do_download()       
      try:
          pkg_resources.require("setuptools>="+version); return
      except pkg_resources.VersionConflict, e:
          if was_imported:
              print >>sys.stderr, (
              "The required version of setuptools (>=%s) is not available, and\n"
              "can't be installed while this script is running. Please install\n"
              " a more recent version first, using 'easy_install -U setuptools'."
              "\n\n(Currently using %r)"
              ) % (version, e.args[0])
              sys.exit(2)
      except pkg_resources.DistributionNotFound:
          pass
  
      del pkg_resources, sys.modules['pkg_resources']    # reload ok
      return do_download()
docs: Automatically find/download setuptools and make it available on sys.path
  
      `version` should be a valid setuptools version number that is available
      as an egg for download under the `download_base` URL (which should end with
      a '/').  `to_dir` is the directory where setuptools will be downloaded, if
      it is not already available.  If `download_delay` is specified, it should
      be the number of seconds that will be paused before initiating a download,
      should one be required.  If an older version of setuptools is installed,
      this routine will print a message to ``sys.stderr`` and raise SystemExit in
      an attempt to abort the calling script.