jupyter-notebook，ImportError：无法导入名称“ Type”

我是Windows用户，并且已经在计算机上安装了Python 3.6。为了使用Jupyter笔记本，我下载了atom。我已经安装了ipython和pandas。在jupyter notebook命令行中输入命令后，我的浏览器没有打开jupyter笔记本，而是显示以下错误消息：

[C:\Users\ELIDAD>jupyter notebook
Traceback (most recent call last):
  File "c:\users\elidad\appdata\local\programs\python\python35\lib\runpy.py", line 170, in _run_module_as_main
    "__main__", mod_spec)
  File "c:\users\elidad\appdata\local\programs\python\python35\lib\runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "C:\Users\ELIDAD\AppData\Local\Programs\Python\Python35\Scripts\jupyter-notebook.EXE\__main__.py", line 5, in <module>
  File "c:\users\elidad\appdata\local\programs\python\python35\lib\site-packages\notebook\__init__.py", line 25, in <module>
    from .nbextensions import install_nbextension
  File "c:\users\elidad\appdata\local\programs\python\python35\lib\site-packages\notebook\nbextensions.py", line 610, in <module>
    from .extensions import (
  File "c:\users\elidad\appdata\local\programs\python\python35\lib\site-packages\notebook\extensions.py", line 8, in <module>
    from tornado.log import LogFormatter
  File "c:\users\elidad\appdata\local\programs\python\python35\lib\site-packages\tornado\log.py", line 34, in <module>
    from tornado.escape import _unicode
  File "c:\users\elidad\appdata\local\programs\python\python35\lib\site-packages\tornado\escape.py", line 27, in <module>
    from tornado.util import unicode_type
  File "c:\users\elidad\appdata\local\programs\python\python35\lib\site-packages\tornado\util.py", line 21, in <module>
    from typing import (
ImportError: cannot import name 'Type']

那么，有什么问题呢？我是python和jupyter笔记本的新手。非常感谢你。