jupyter notebook / Failed to start the kernel due the KeyError

问题

My jupyter notebook doesn't start due the dead kernel with following Kernel error:

Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/tornado/web.py", line 1512, in _execute
    result = yield result
  File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/tornado/gen.py", line 1055, in run
    value = future.result()
  File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/tornado/concurrent.py", line 238, in result
    raise_exc_info(self._exc_info)
  File "<string>", line 4, in raise_exc_info
  File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/tornado/gen.py", line 1069, in run
    yielded = self.gen.send(value)
  File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/notebook/services/sessions/handlers.py", line 67, in post
    model = yield gen.maybe_future(sm.get_session(path=path))
  File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/notebook/services/sessions/sessionmanager.py", line 170, in get_session
    return self.row_to_model(row)
  File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/notebook/services/sessions/sessionmanager.py", line 209, in row_to_model
    raise KeyError
KeyError

回答1:

In my case, the issue originated from having prompt-toolkit requirement conflict in jupyter-console and ipython.

You can use pip check to make sure whether you have the same problem. If the output is something similar to my output below, you have to fix the broken packages issue.

>>> pip check ipython 
ipython 5.0.0 has requirement prompt-toolkit<2.0.0,>=1.0.3, but you'll have prompt-toolkit 2.0.9 which is incompatible. 

>>> pip check jupyter-console 
jupyter-console 6.0.0 has requirement prompt-toolkit<2.1.0,>=2.0.0, but you'll have prompt-toolkit 1.0.15 which is incompatible.

The quick fix is to try the solution originally mentioned here.

pip uninstall prompt-toolkit 
pip install prompt-toolkit==1.0.15 
pip uninstall jupyter-console 
pip install jupyter-console==5.2.0

来源：https://stackoverflow.com/questions/54437305/jupyter-notebook-failed-to-start-the-kernel-due-the-keyerror

标签

python-3.x

pycharm

jupyter