由于KeyError，jupyter notebook /无法启动内核

Question

我的jupyter笔记本无法启动，因为死内核存在以下内核错误：

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

Answer 1

就我而言，问题起源于prompt-toolkit和jupyter-console的ipython要求冲突。

你可以使用pip check来确定你是否有同样的问题。如果输出类似于下面的输出，则必须修复损坏的包问题。

>>> 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.

快速解决方案是尝试最初提到的解决方案here。

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