TypeError: 'type' object is not subscriptable

[kmahsi]

Hi
I've installed jupyter notebook with these commands:
python3 -m pip install --upgrade pip‍‍‍
python3 -m pip install jupyter
And when I run jupyter notebook

I get following error:

Traceback (most recent call last): File "/home/kamran/workspace/UT/Semester6/AI/p2/env/bin/jupyter-notebook", line 6, in <module> from notebook.notebookapp import main File "/home/kamran/workspace/UT/Semester6/AI/p2/env/lib/python3.5/site-packages/notebook/notebookapp.py", line 47, in <module> from zmq.eventloop import ioloop File "/home/kamran/workspace/UT/Semester6/AI/p2/env/lib/python3.5/site-packages/zmq/eventloop/__init__.py", line 3, in <module> from zmq.eventloop.ioloop import IOLoop File "/home/kamran/workspace/UT/Semester6/AI/p2/env/lib/python3.5/site-packages/zmq/eventloop/ioloop.py", line 21, in <module> from tornado import ioloop File "/home/kamran/workspace/UT/Semester6/AI/p2/env/lib/python3.5/site-packages/tornado/ioloop.py", line 45, in <module> from tornado.concurrent import ( File "/home/kamran/workspace/UT/Semester6/AI/p2/env/lib/python3.5/site-packages/tornado/concurrent.py", line 175, in <module> future: Union["futures.Future[_T]", "Future[_T]"], value: _T File "/usr/lib/python3.5/typing.py", line 552, in __getitem__ dict(self.__dict__), parameters, _root=True) File "/usr/lib/python3.5/typing.py", line 512, in __new__ for t2 in all_params - {t1} if not isinstance(t2, TypeVar)): File "/usr/lib/python3.5/typing.py", line 512, in <genexpr> for t2 in all_params - {t1} if not isinstance(t2, TypeVar)): File "/usr/lib/python3.5/typing.py", line 190, in __subclasscheck__ self._eval_type(globalns, localns) File "/usr/lib/python3.5/typing.py", line 177, in _eval_type eval(self.__forward_code__, globalns, localns), File "<string>", line 1, in <module> TypeError: 'type' object is not subscriptable

/home/kamran/workspace/UT/Semester6/AI/p2/env/
is my virtualenv directory address

[kevin-bates]

Duplicate of #4439. Please downgrade tornado to < 6.0.

[kmahsi]

@kevin-bates
Thank you very much!
I searched but I didn't find anything similar.
Thanks

[kevin-bates]

No worries - I suspect the first issue was arriving as you were searching. 😄