ImportError:在python 2上安装zip时没有名为util的模块

I am trying to install zip on python 2 and encountering this problem. It seems from the progress of installing Markdown. Can anyone help me ? Thanks so much !

    Complete output from command python egg_info:
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/tmp/pip-build-3mQ_bJ/Markdown/", line 39, in <module>
        __version__, __version_info__ = get_version()
      File "/tmp/pip-build-3mQ_bJ/Markdown/", line 32, in get_version
        import importlib.util
    ImportError: No module named util