如果启动jupyter notebook报错：
[C 18:49:50.816 NotebookApp] Bad config encountered during initialization:
[C 18:49:50.816 NotebookApp] The ‘contents_manager_class‘ trait of a NotebookApp instance must be a subclass of ‘notebook.services.contents.manager.ContentsManager‘, but a value of class ‘traitlets.traitlets.MetaHasTraits‘ (i.e. <class ‘notedown.contentsmanager.NotedownContentsManager‘>) was specified.
是因为启动jupyter默认加载notedown插件却发现没有安装造成的。
安装notedown插件：
pip install https://github.com/mli/notedown/tarball/master
运行Jupyter并加载notedown插件：
jupyter notebook --NotebookApp.contents_manager_class=‘notedown.NotedownContentsManager’
【可选项】默认开启notedown插件
首先生成jupyter配置文件（如果已经生成过可以跳过）
jupyter notebook --generate-config
将下面这一行加入到生成的配置文件的末尾（Linux/macOS一般在~/.jupyter/jupyter_notebook_config.py)
c.NotebookApp.contents_manager_class = ‘notedown.NotedownContentsManager’
之后就只需要运行jupyter notebook即可。
