conda - Jupyter实验室无法启动

Question

我今天更新了我的conda环境。以前，我可以从终端启动jupyter Lab。更新后(包括安装theano，但我猜这是不相关的)，出现以下我不理解的错误:

marcel@flaptop:~$ jupyter lab
Traceback (most recent call last):
File "/home/marcel/anaconda3/bin/jupyter-lab", line 7, in <module> from jupyterlab.labapp import main
File "/home/marcel/anaconda3/lib/python3.6/site-packages/jupyterlab/labapp.py", line 7, in <module> from notebook.notebookapp import NotebookApp, aliases, flags  
File "/home/marcel/anaconda3/lib/python3.6/site-packages/notebook/notebookapp.py", line 45, in <module> ioloop.install()
File "/home/marcel/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'

有人知道这里发生了什么吗？

Answer 1

似乎是Tornado版本5。这里有讨论:
Install Jupyter Notebook on Miniconda

pip uninstall tornado
pip install tornado==4.5.3

如上面的链接中所述，为我修复了该问题。