我將 python 版本從 3.5 升級到 3.6 後，Anaconda 無法開啟

Question

有人可以幫我擺脫這個錯誤嗎？

jupyter-notebook這是我使用以下命令將 python 3.5 升級到 3.6 後在終端機中 輸入時顯示的錯誤：conda install python=3.6

Traceback (most recent call last):
     File "/usr/local/anaconda3/bin/jupyter-notebook", line 7, in <module>
from notebook.notebookapp import main

     File "/usr/local/anaconda3/lib/python3.6/site-packages/notebook/notebookapp.py", line 45, in <module>
     ioloop.install()

     File "/usr/local/anaconda3/lib/python3.6/site-packages/zmq/eventloop/ioloop.py", line 210, in install
assert (not ioloop.IOLoop.initialized()) or \

     AttributeError: type object 'IOLoop' has no attribute 'initialized'