Jupyterlab 的安装失败：ImportError: cannot import name 'constants' from partially initialized module 'zmq.backend.cython'

[xuekang]

问题：
ImportError: cannot import name 'constants' from partially initialized module 'zmq.backend.cython' (most likely due to a circular import) (C:\Users\User\AppData\Roaming\Python\Python38\site-packages\zmq\backend\cython_init_.py)

解决方案：
pip uninstall pyzmq
pip install pyzmq