ImportError: cannot import name 'ensure_dir_exists'

   解决办法：升级jupyter_core和jupyter_client

pip install --upgrade jupyter_core jupyter_client

　在升级过程中留心可能出现的警告　

    升级后可能会出现valueerror: signal only works in main thread，原因是包版本冲突了

   >解决办法：

pip show pyzmq ipykernel
#pyzmq==18.0.0对应ipykernel==5.
pip install --upgrade ipykernel

标签：core,upgrade,jupyter,name,ipykernel,ImportError,pyzmq,pip,exists
来源： https://www.cnblogs.com/zutterlly/p/12506130.html