code: def download_pip(env, requirements):
      
      if config.installation_cache_folder() is None:
          raise EnvironmentSetupError("Local installation cache folder not "
              "defined but required for downloading a pip installation.")
      # Installation cache folder needs to be explicitly created for setuptools
      # to be able to copy its downloaded installation files into it. Seen using
      # Python 2.4.4 & setuptools 1.4.
      _create_installation_cache_folder_if_needed()
      try:
          env.execute(["-m", "easy_install", "--zip-ok", "--multi-version",
              "--always-copy", "--exclude-scripts", "--install-dir",
              config.installation_cache_folder()] + requirements)
          zip_eggs_in_folder(config.installation_cache_folder())
      except (KeyboardInterrupt, SystemExit):
          raise
      except Exception:
          raise EnvironmentSetupError("pip download failed.")
docs: Download pip and its requirements using setuptools.